Im heading west by foot from oklahoma and was wondering if you guys could give me advice on some lite gear?

I hitchhike and head to the wilderness on occasion and im usually not very prepared forthewoodsNOOB).I find myself carrying a pack that is too heavy and consistently uncomfortable sleeping situations. Wouldn't really be a huge problem i guess, but i plan to be gone for 6 months this time and would like to be as comfortable as possible.

the terrian will be a combination of mountain, desert, and even urban. it will mostly be warm and sometimes rainy.. if that helps you narrow it down.OhIMtrying not to spend more than $500!

anything im overlooking?id be happy for your advice!