You can represent yourself ("pro se") in the patent process, but it can be helpful to work with a patent lawyer. Patent lawyers are typically legal professionals with a technical background, and they are skilled at drafting the complex legal language that goes into patent claims.
The USA is a "first to file" country. That means it doesn't matter who invented something first; it matters who submitted their paperwork first. The USPTO offers a way for inventors to file basic paperwork very quickly, in order to get the earliest possible date. This is called a provisional patent application. However, if you submit a provisional application, you must submit the full application within one year.