Sunflower is written and siung by Post Malone and Swae Lee.

The song was made in 2018, when the movie "Spider-Man into the Spider-Verse" was released.

release needs to be past tense here.

I think it's my favourite movie with Spider-Man across the Spider-Verse because the universe is amazing and the drawing areanimation is just incredible.

Animation is used to refer to drawings in film or TV.

I want to learn how to playing Sunflower byon the guitar but it's a bit difficult so I need time but I will be very proud of myself when I will finish.

how to play instead of playing.
on the guitar instead of by the guitar.

Sunflower is written and siung by Post Malone and Swae Lee.

sing should be past tense

The song was made in 2018, when the movie "Spider-Man into the Spider-Verse" was released.

past tense on release

I think it's my favourite movie, along with Spider-Man across the Spider-Verse, because the universe is amazing and the drawing areart style is just incredible.

I didn't correct it, but the spelling of favourite you have is the British spelling and for American English it is favorite. Both are right, so I guess it depends on what you want to use, but my spell check does flag it lol. Spider-Man across the Spider-Verse in this sentence is extra information and typically when that is the case you bookend it with commas. I had to refresh what the grammatical term is called but it is a "non-restrictive clause". The rule of thumb is if you could remove the clause and the sentence would still work, you format it like how I did. I also changed drawing to art style because while yes it is an animated movie and it is drawn, we just don't typically refer to it as a "drawing" since drawings don't move.

So, when I listen Sunflower, it makes me happy because I think about my favourite movies.

I want to learn to playing Sunflower byon guitar, but it's a bit difficult so I. I'll need time to perfect it, but I will be very proud of myself when I will finishdo.

Some minor tensing and comma corrections. I also broke the sentence into two and made the second one flow a little better by swapping finish with perfect and putting it at the front.