Hi.
For most first-time authors, agents and publishers are going to want to see a book between 75-85k. Larger books are usually not worth the risk or the expense. You are going to
have to get an agent if you want to get in with any of the major publishers so your first job is to have an absolutely polished manuscript, then write a quality query letter, send it to agents in your genre and see if you get any bites. Keep in mind this process is going to take a long, long, long time. If you get an agent and they send your book out on submission, you are looking at 4-6 months, at least, per round of submissions and you could go 3-4 rounds before you get any interest at all, if you do at all. Even if you get a contract, it will be an average of 18-24 months before the book is actually published. This is not a fast process by any means.
The thing to remember about self publishing is that you have to learn how to be a publisher as well as a writer. You have to know how to find a good editor, cover designer and formatter, or how to do it properly yourself. Not to mention the whole profession of marketing. It can take years and many books before one sells regularly.