Do the timing belt. You can open the front plastic cover with 10 mm spanner and see whether you can see any cracks or broken threads. Then it is high time to replace it.
But if you can see white lettering very clearly, I think the belt is still"new" but who knows, it may be old.
I have a 92 Toyota Sprinter (Geo prizm), it had 184 K miles when I bought it. I opened the t-belt case! Jesus! I have never seen a belt like that before. It was not even black. Even the color of the belt has been changed with cracks all around like a dried-up lake bottom!
Thankfully I got it replaced. I think it was the OEM belt!
Next, drain all the oil (engine + OEM FILTER, transmission, rear axle, front axle transfer case- if 4x4) and refil with good oil. I use Valvoline synthetic blend for the engine and valvoline 75-80 for axles. For transmission, use TOYOTA OEM oil. About $5 a qrt. Also check Power steering oil, drive belts. Grease the drive shaft(s) and york if applicable
Get a OEM air filter ($20) and OEM spark plugs ($3 each x 6 if V6). Buy all from a dealer.
Radiator! change this if it still says "toyota" on the top tank. OEM Radiator is good for 10 years. any aftermarket, about 4-5 years.
I did all this and my truck is good as new! will drive to the moon only with enough gas.
I used a flex a lite 12x5x0.75 inch transmission cooler $25 (ebay) I fixed it at the the lower valance opening right below the A/C filter so it gets enough air when moving. Make sure to have a metal mesh before the cooler to protect it from road derbies.
Take care of your Toyota, it will take care of you!