Need help with weirdness

Hi
I am working with WP for the first time in a couple of years. I am having a lot of strange problems. I will put something into a page, set it to come out black and then half of the text will come out the default gray. Or it will change three views later, seriously it has done that.
My biggest current ptoblem is the actual home page has vanished from the pages, so I cannot edit it. the program has never been able to hold onto the formatting for the index page also. Everything should be aligned left. I set it up that way, look at the page after the update and it is right. I will come back an hour later and the formatting iss gone, Paragraphs are suddenly indented, etc. I really need to get to edit more on the page but as i said, the home page is no longer there in the pages list and therefore I can’t edit. Please someone give me some help. This is so frustrating there are no words.