Hello Id like to hook my rv up at home. how and what kind of wire and box should I use, i have a fetached garage that i can go to but what should i do and how to wire any help would be great also its no more than 25 or 50 ft from the box to the rv.
Is your RV's shore power connection 30-amp, or 50-amp? Each uses a different receptacle and, obviously, different wire and circuit breaker size.
I did this for my RV, which uses 30-amp shore power, so that's what I'll describe:
To connect to your house panel, you'll need a 30-amp, single pole breaker. For the conductor I used 10/2 UF wire, which is approved for direct burial (burial depth varies by local code - I buried mine 24 inches). You can also use individual conductors in conduit, which may be more expensive. The receptacle you need is unique to RVs; it is a NEMA TT-30R. Places like Lowe's and Home Depot may not carry them. The easiest thing to do is go to an RV place, where you can buy the receptacle mounted in a weatherproof box.
I know this is a DIY site, but the way you phrased your question suggests to me that you don't know much about electricity or electrical work. If that's not the case, I apologize. If it is, then please have somebody help you who is familiar with it. This job is not complicated, but can be dangerous - parts of your breaker panel will be live even if you open the main breaker.