a pA Problem

All words should be capitalized in a title besides “a, the, an, and, for, but, or, for, nor, in, on, to, at, or by” when they are not the first word of a title.

iI have a problem , i totallyI can express what iI want to say but the words that iI use isare very beginner , and i need to usI want to learn more advanced vocaburallary

“I” is always capitalized. Instead of using “is” we’d use “are” because “words” is plural. “Are” is used to refer to plural nouns.

a pA Problem

iI have a problem , iI totally express what iI want but the words that iI use isare very beginner , and iI need to use advanced vocaburalylary instead.

aA problem

iI have a problem , i totally. When I express what iI want butsay, the words that iI use is very beginner , and i needsimple like a beginner. I would like to use a more advanced vocaburalylary

a pA Problem

iI have a problem , i totally. I can express what iI want, but the words that iI use isare very beginner rudimentary, and iI need to use more advanced vocaburalylary.

iI have a problem , i totally express. I'm able to communicate what iI want to say, but the words that iI use isare very beginner , and i needsimple/basic. I want to use more advanced vocaburallary

Don't forget that every time you use I, it has to be capitalized. I would first advice you to focus on learning modal verbs (like could, can, able, would, etc.) since some of your sentences needed them. Then, I would also pay attention to your sentences to see if you need to use is or are since, yet again, you switched them a couple of times. To answer your question, I would advise you to start immersing yourself in the language by watching shows, videos, etc. You'll be able to see how people communicate, and you can start writing down and studying words you come across that you think are important/you would use.

a pA Problem

Words in titles need to be capitalized (Except for conjunctions unless it is the first word in the title)

iI have a problem , i tota: I fully express what iI want, but the words that iI use isare very beginner , and iasic. I need to use more advanced vocaburalylary.

"I" needs to be capitalized (same with "I'm" and other combinations that use I)
Are instead of is because it is multiple words, not just one.
Usually, people don't use "totally" in a situation like that; it's usually used like that in slang. Using "fully" gets the point across better without seeming informal.
"Basic" is better in this scenario, as it means simple.
There is only a space after punctuation, not both before and after.
While having that last chunk there technically works, it flows nicely to have it as its own sentence.