This is a subtle, deep, not always logical and ever changing field.
If you decide to tackle it in your own, the standard, and good, answer is
Patent It Yourself: Your Step-by-Step Guide to Filing at the U.S. Patent Office
The author maintains a web site with errata and updates to law and regulations. There is quite a bit of detailed information in this book that has evolved over many editions.
Next I would look for an inventors club in your area. They often have good speakers and it’s valuable to exchange ideas with other inventors.
If the cost of getting help from a professional is really out of reach the USPTO has a pro bono program that mught be active in your location.
You mention claims. They are very hard to write well. I recommend
Invention Analysis and Claiming: A Patent Lawyer's Guide.
However the clever claiming he teaches might not be as effective as it was when it was written.
These books are under a hundred each. The other two or three books I would list are each over $400.
The person drafting the application writes the initial claims. It is hard. Maybe harder is responding after you get an “all claims rejected” office action.
A good resource is the blog Found Persuasive. I’m not sure it has been updated lately. The most significant patent blog overall is PatentlyO but don’t get caught up by the arcane and surprisingly insulting comments patent attorneys make to each other in the comments areas.
If your invention is chemical, biological or software your chances of success drop considerably.