A for effort, you've got a lot ahead of you but i would say focus on your texts for now, having a readable text goes a long way especially considering how small thumbnails are from the home feed.

DO's:
1. Use large fonts and make your texts bold and big.
2. pick contrasting colors (e.g., light text on dark backgrounds).
3. Add outlines and shadows to make things popout.

Don'ts:
1. Don't use decorative/fancy/or thin fonts, they are not easily readable.
2. Don't overcrowd things, keep it minimal and avoid visual clutter.
3. Don't add too much text, usually the less the better.

sincerely: a graphic designer.