97 Dodge Dakota idle problem and questions?

[Ben]

I just bought a Truck. 97 Dakota with only 107k miles. i checked all fluids and the trans fluid looks new! also the gear shifter doesn't line up perfectly with the gear lights. I'm assuming it has had a new transmission or rebuild lately shifts smooth and seems fine. think it could have been rebuilt? my other question is that when i start is in the morning it will idle lower than it seems it should for being cold. shouldnt it ilde higher for a little bit and go down when it warms up? well it idles kinda low and then rps will seurge to almost 2k rpms if i get in and give it some gas after a while and rev it normally will stop. now mind you i just bought the truck and have had it for about 20 miles i don't drive far to and from work. i planned on doing air filter and gas treatment and injector cleaner. could it be the tps censer? my first thought was the fuel filter but i did some research and thats in the gas tank! let me know what you think of every thing