Do you have any of the maintenance records for the truck? If not, you can go to the Toyota website, plug in your VIN and get whatever they have in their database for your truck. If the PO had it serviced at a Toyota dealership, it should be there. If not, it doesn't mean good work wasn't done, just not recorded.
Be aware that repairs on these trucks are expensive, but they last a LONG time. OEM parts are highly recommended instead of aftermarket parts. These trucks have been around long enough that original owners have tried multitudes of aftermarket parts, only to find that the OEM ones are what lasts the longest.
Great vendors for OEM parts are:
@cruiserdan
@beno
and a couple others. I don't know them because I have not needed to use them. (Sam Stewart)
Things to look for on your particular model:
Head Gasket (did the PO already have it done?)
Oil Pump seal and Front Main Seal
Distributor O-Ring (dizzy o-ring)
Valve Cover gasket
Spark Plug Tube Seals
Front axle rebuild (brakes, rotors, wheel bearings, seals, Birfields)
Rear axle rebuild (brakes, rotors, wheel bearings, axle seals)
Lube drive shafts (DS) and tie rod ends (TRE's)
Check the coolant. Best is RED. Green is OK. Brown is a problem, orange is a problem. If either brown or orange, it needs to be flushed multiple times and exchanged with RED.
Pesky heater Hose (PHH). Left side down near bottom of block. Should be changed every 150K as PM.
Heater hoses for rear heater (under truck)
Thermostat: ONLY use OEM.
Wiring harness melting near the rear of the head due to the harness being close to the EGR.
OEM Spark plugs
OEM Spark Plug Wires
OEM Distributor cap and rotor
Those are the top 13 items that occur on your year.
Your truck looks great! Gather a few metric tools and get to work! These are easy to work on, get a Factory Service Manual (FSM) from one of the folks here on 'Mud. (Usually digital and free)
Do your baselining and make sure it is good to go!
Engine Oil
Coolant check
Transmission oil check
Transfer Case Oil Check
Front and Rear differential oil check
Knuckle ball grease (Birfield grease)
Hoses for cracks or soft spots
Brakes
Spark Plugs and wires
Drive it and have FUN!
These typically get 12-16 MPG depending on driver and terrain.
I'm sure others will chime in with their additions to the list.