An expensive way to "test the waters with" if you dont mind me saying. Do your homework.
Check out how many others are already doing this in your area and consider whether your idea is a goer or not. ie amount of competition. It can get very very nasty out there....
Are you looking for a hobby atleast at first. If so, do you consider spending all day, or 2 or 3 days at events working, to be the right kind of hobby for you?
Do you then consider the cost of investment to be worth it, if it doesnt pay off. Or is that not a consideration for you?
These are serious considerations.
If you are looking to make legitimate income, whether it be a supplement to a regular job or because you need to provide yourself with a job, is it worth doing ( cost / benefit analysis)?
Also consider if you make it a success, you will become tied to it and there is no going back or you will lose your clients. IE, your regulars rely on you, and if you decide to back off, they will fill your slot will immediately and you wont get it back, so do also think of the serious nature of the responsibility you are taking on or it wont work ie....your level of committment. Trying to find helpers or a "manager" when you want to take time off or go on vacation, can be very difficult...unless you ahve come to some kind of amicable arrangement with another van owner where you can help eachother out.....
Consider this type of business lends itself to your employees easily scamming you by putting your income in their pocket....so you will need to be there virtually all the time its is a very onerous committment if you want to make it work, do it for a couple of years intensively until youve had enough, then sell ( if you can) and go to something else.