@19Evangeline94 based on experience with those messages, its best to not engage and ignore them. Like block and delete them.
On the second one, i would say that having a beta reader would be best. Because having them means that they could point out or correct any mistakes. I would suggest to use google docs as well since it has a grammar and spelling checker available before publishing it, and it could keep your drafts that way if wattpad error or something, at the very least you would have a copy of your story.
But yeah, let people know you are looking for a beta reader, or join a discord server that beta readers for others. I can’t really say for sure which are they since, i don't have a beta reader and don't want one lol. But yea, those are your options based on my opinion.