Finally Home (1st Bike!)

2005 Suzuki DR200 with 5200 miles. I've done a little but of research and I've been told these are great first bikes, I got it from a friend at a good price. I live in an area with plenty of forest roads and BLM trails and I've been wanting one for a while. I've ridden a few dirt bikes and street bikes here and there but I don't know a whole lot about taking care of them. What are some maintenance tips I need to look for and maybe some upgrades I should go for? TIA (My buddy also threw in a knobby tire for the back so I have that)