My thoughts? Yes and no.
When it comes to writing for fun on these free to read sites like Wattpad, having good/flawless grammar really doesn't matter. Not unless you're out here trying to get noticed and land a publishing deal - then, of course, it helps to have perfect grammar. If you write primarily for fun, don't stress out about commas and apostrophes. Don't put that kind of pressure on yourself, haha.
Free Sites To Help Your Grammar/Punctuation:
Grammarly > https://www.grammarly.com/
Ginger > http://www.gingersoftware.com/
ProWritingAid > https://prowritingaid.com/