Well, probably a lot more information is needed to give you helpful advice.
- Paying off loans vs investing largely depends on the interest rate - see investment order posted above.
- What’s your current rent? RVs can be money pits both when used for the odd weekend “camping”, but also sometimes when lived in full time. I have a coworker that lives full time in a nice RV, I’ll bet between the cost of the pad he rents and the money spent on upkeep and repairs (he DIYs at least half of these) it costs about the same as renting an apartment in our somewhat HCOL area. Your situation may be different, maybe you are an RV mechanic or will get lucky with one that is extremely reliable.
- What is the side-business? How’s the 10k going to be spent? If you have a solid plan and 10k is enough, then go for it. If you don’t have a solid plan, I’d recommend putting in no money, or as little money into the business as possible until it’s looking like it’ll pan out. If you have a solid plan, but 10k is the minimum needed, I’d keep a lot more than 10k aside in case the business takes off and you need to throw money to keep up with growth