Not really. You need just a knee pads and they are part of the product.
Well, we tried the wheel on the gravel and, to be honest, it is not very pleasant experience, but in general, you can practice anywhere. Just make sure that you have clear space in front of you. Especially kids and pets could easily ruin your training when buzzing around.
Please apply standard rules and use common sense before and during training. In case of any doubts, your GP might give you advices and recommendations. Especially in case of any health problems.
It is definitely essential to warm and stretch your muscles before training. Same as with any other fitness equipment.
To buy the RamCarver at the bargain on Amazon and start!