WELCOME TO THE FORUM!!! In addition to the opinions you receive here (there will likely be lots) do your own research and solicit ideas from people you know that have RVs.
There are many things to consider. First of all, will you be purchasing the RV to stay in one place, or will you be moving it frequently? You'll have to consider the cost of where you park it as part of the cost. For example, if you park in an RV park, you'll have monthly rent and utility costs.
Since you don't have steady income, and don't have a lot saved, it will make it tough to purchase from a dealer on credit, but not impossible. Go to several RV lots and see what's available. Quite often, they can be quite flexible with financing in order to keep your montly payments low.
In addition, you'll have to purchase a TV (Tow Vehicle). You'll want to make sure you buy a TV that is strong enough to pull the RV, and reliable too.
Spend a few days researching this site, asking questions and getting educated. Good luck to you.
Jim
2016 Ford F350 Turbo Diesel SRW 4x4
2017 Grand Design Reflection 297RSTS
2013 Ford F350 Turbo Diesel SRW 4x4 (Destroyed by fire - 8/29/16)
2014 Grand Design Reflection 337RLS (Destroyed by fire - 8/29/16)