Just bought my first DSM and having a bunch of problems

[Kracka]

LOL considering its a DSM consider yourself lucky to have only these issues. These all probably come down to the car needing some routine maintenance; do all maintenance items before modding the car at all.

Sounds like it could use some fresh coolant (50/50 mix of water and antifreeze), a new thermostat, a new radiator cap, a new valve cover gasket with spark plug donuts, and possibly some new sealant on the oil pan. Clean up the oil seepage on the pan though to make sure you can pin point exactly where its coming from to make sure it really is the pan. All of this stuff really won't cost you that much and won't take more than a few hours to do.

After you take care of those issues, you should do the general stuff like drivetrain fluids, spark plugs, belts, spark plug wires, etc. unless you have documented proof from the previous owner that they were done recently. Hopefully Twack gets in here and can lend some some additional insight to what the car needs and what has been recently done.