YOU TOTALLY SHOULD SINCE I'D BE THE FIRST ONE TO READ AND SPAM ON IT!
Also, I don't think there's anything to learn about writing fanfiction lmao, JUST GO ALL IN!
Though, if you want to see if there are any grammar or spelling errors or ways to make a sentence better, I can recommend two websites to you.
1) quillbot
2) thesaurus
If you need any help anywhere/an editor then hmu! <3