Suggest you read the owners manual.
Toyota is now very specific about which weight of oil to use. One reason is the engine clearances are now tighter. Thought the 0W-20 was only available in synthetic, but?
What oil change interval does the manual state?
Toyota is going to 10K now with some models, they claim this is OK. There was another post at this website on the 10K oil change interval, do a site search. If asking about this everyone has there own opinion.
Synthetic will outperform mineral oil. Better lubrication and ability to maintain it over a longer period of time. If you want the car to last forever and can afford it use a synthetic.
Mobil 1 is a top rated synthetic but there are others. But some owners use Wal-Mart SuperTech.
Suggest you use the lowest grade of fuel that does not result in engine pinging. The owners manual should state this. There is no benefit in using a higher grade fuel then recommended.
If going using a synthetic make sure the oil is fully synthetic and not a blend of mineral and synthetic.