You found a great place to learn your new smoker, meet some new friends, and make some new memories in your backyard!
For your RiverGrille did you get the cattleman, stampede, or farmer model? I think the Farmer and Cattleman have the offset fire box. The stampede is just a barrel. If you got the farmer or cattleman then you have what's called a horizontal offset smoker. You can poke around/research using the search function (magnifying glass) at top of the page. when you are looking for info on your smoker (how to modify/techniques/tricks) or if you are asking for help it'll help if you clarify you are using the horizontal offset.
I don't have your brand, but I use the style. There are some easy mods you can do to improve it. But, for now just dive in and try a few things to get a feel. Invest in a wireless meat probe, many get maverick or iGrill. Internal Temp is critical to smoking good food.
It's difficult to maintain a steady low temp with store bought offsets, even with some mods, so don't get too freaked out if you see your cooking temps fluctuate drastically at first. You and your family won't notice difference!
Don't use wood chips, most recommend natural charcoal with wood Chuncks mixed in unless you are going pure splits (logs). Be wary of smoldering wood. You want a clean smoke.
Have fun learning! Be sure to ask if you need help! Most of us here have had a lot of mentoring by the old salts, but be ready for conflicting opinions!