Welcome to the forums. Yes, it's a 4-stoke. It holds about 2.2 quarts and make sure you use oil that's safe for wet clutch applications. Most automotive oils contain friction modifiers that will cause the clutch to start slipping. Also, when you change the oil filter, make sure you don't put it in backwards or it will block the oil flow and damage the engine. And no, there's no transmission fluid to change. On that model, the engine oil also lubricates the transmission.
Bolt pattern for the front and rear both, is 4/110.
On the front end being loose, it could be a few things. It could be bad wheel bearings, worn king pins, or worn j-arm bushings or a combination of all of those.
Most 4-wheeler problems are caused by a loose nut connecting the handlebars and the seat!!
You only need two tools in life -- WD-40 and duct tape. If it doesn't move and should, use the WD-40. If it shouldn't move and does, use the duct tape.