Welcome Danilo! My suggestion is to narrow the search some for what exactly you are looking to do and what type equipment you plan to use. How do you plan to camp, etc.? I generally start by looking at maps and satellite views of the area I am interested in. I like to look for dispersed camp sites so National Forests are often targeted. If you plan to stay in organized campgrounds they often show up on Google Maps and other places.
You like mountains? Head West to the Rockies. There are lots! FYI, many of the high passes will be closed until nearly mid-summer. My plan this year is to start from the South and work North like you seem to be doing. Last year I started in mid-July and went North to Wyoming, Montana, Idaho, and a little bit of N. Colorado. That worked well but I can see where some of the high passes would be problematic. Especially this year they may have gotten more snow than last year. There are some sites that keep up with that but I don't have that info presently at hand. Good maps are always a plus. Good Luck in your travels and ask questions here. There is much knowledge among this community.