Hiya, sorry you are having trouble getting your forms to work.
This Common Issue is the first port of call to debug any forms issues.
We also recommend trying to search the forums or look at topics tagged Netlify forms if you haven’t already. There are quite a few topics on “page not found form” - it’s likely your question was already asked by someone else!
If you are still having problems, please provide more information such as what you have already tried, and a link to your live form. 