Today I am intencesely practiceding vocabulary and reading.

If you mean that today is a day where you intend to focus on these two areas, then the past tense can be avoided and the above correction sounds natural.

While I listened to a podcast, I always thinkedrepeatedly thought about something sweet because I was really hungry.

the clause with "while" can go after "hungry" without a comma, or it can go at the beginning with a comma like I added. Also, "always" sounds like it is still happening or like it happened a long time ago and then stopped when enough time went by. For example:

I always drive carefully.

When I was little, I always had a night light.

The main part of the podcast for me was about using the singular they/their.

Before, it was "a podcast" because it was unspecified and it was being introduced for the first time.

Now, it is "the podcast" because the reader knows that you are referring to the same one as earlier. "The podcast" means if someone asks "which podcast?" we could tell them "the one already mentioned above."

I've been interested how I should use that for a long time, so now I got an answer to all my questions.

The phrase is "for a long time." Alternatively, "since a long time ago."

you could also say "for all my"

you could also say "all of my questions"

Also, "a" is used when the next word doesn´t start with a vowel sound. "An" is used when the next word begins with a vowel sound. For example:

I ate an apple.

I ate a banana.

So now I got a answer on all my questions.

"So" is used here as a conjunction, so it needs to be attached to another clause in the same sentence. If you didn´t want to combine the sentences, you could also say something like this:

Now I got an answer to all of my questions.

I have a hard time with vocabulary because I don't know what is the bestter way of learning new words.

The phrase is "to have a hard time."

- I have a hard time, she has a hard time, we have a hard time, et cetera.

- "better" compares at least two choices. When you mean "the optimal choice" or "the choice with the highest benefits," "best" is used.

I wonder, can somebody give me an advice ion ithat?

It is hard to explain why "in" doesn´t work here in this way. Some examples:

1. give me advice for that
2. give me advice with that
3. give me advice on that
4. give me advice in that area

all would be acceptable

also, advice is not usually used like a single thing. You might see "give me a piece of advice," but otherwise it is just "give me advice" or "give me some advice" or something like that

Today I am intencesely practiced vocabulary and reading.

I made the smallest adjustment to make it grammatically correct there.

While I listened to a podcast I alwayskept thinkeding about something sweet because I was really hungry.

"While I listened" is specific to a single event while always covers a much larger scope, so they don't go well together.

The main part of the podcast for me was about using singular they/their.

I've been interested in how I should use that a long time.

So now I got a answer ton all my questions.

I have hardtrouble with vocabulary because I don't know what thea better way of learning new words.

"hard" is an adjective and you need a noun after "I have here".

I wonder, can somebody give me an advice ion it?

advice is uncountable, so you don't say "an advice" or "advices".

Today, I am intence practiced vocabulary and readingsely reading and practising using new vocabulary.

While I was listeneding to a podcast, I alwayswas constantly thinkeding about something sweet because I was really hungry.

"Always" is used for habitual actions. When speaking about one time, you would instead use "constantly" or "repeatedly."

The main paroint of the podcast for me was about usinghow to use the singular "they/"/"their."

I've been interested how I shouldin knowing how to use that for a long time.

So now I gothave an answer ton all my questions.

"got" is not wrong, just more colloquial/slang/not as proper

I have hard a hard time with vocabulary because I don't know what the betterof a good way tof learning new words.

Another option is saying "my vocabulary"

I wonder, can somebody give me any advice in it?

Today I am intencesely practiceding vocabulary and reading.

While I listened to a podcast I always thinkeding about something sweet because I was really hungry.

"While I [past tense verb], I [past tense] (+ {optional present tense verb}...)" is the basic structure.

Examples:
"While I [thought] about that podcast, I [was] {listening} to..." (Means the same as: "While I thought about the podcast, I listened to..." or "I listened to XX while I thought about that podcast.")
"While I [ran], I [thought] about {going} to the baseball game." (Also: "While I ran, I thought." or "I thought about going to the baseball game while I ran.") ('going to the baseball game' can be left out if the additional information isn't necessary')
"While I [ate], I [decided] I to go {swimming} today." (Same as: "While I ate, I decided." or, more naturally, "I decided while I ate." or "I decided to go swimming while I ate.")
"While I cleaned, I was singing." (Same as: "While I cleaned, I sang." or, more naturally, "I sang while I cleaned.")

The continuous present tense verb can be
1) Combined with the second past tense verb to become past tense itself for the same meaning ("While I ate, I drank.")
2) Only provides additional context for the second verb and can be left out entirely. ("While I ate, I thought." For situations where what the speaker thought about is only implied or otherwise not explicitly stated.)

The mainost important part of the podcast, for me, was about using singular they/their.

I've been interested in how I should use thatit for a long time.

More natural: "I've been wondering how that worked for a long time." / "I've been wondering how it worked for a long time."

So now I got ahave the answer ton all my questions.

I have a hard time with vocabulary because I don't know what thea better way of learning new words.

I wonder, can somebody give me an advice ion it?