Car has a hard time accelerating up hills?

The first thing I would do is check the transmission fluid.

Here is a guide to help:

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

Also, you should do a normal tune up by replacing the spark plugs and fuel filter. I would also clean the throttle body as well.

These guides can help walk you through the repairs:

https://www.2carpros.com/articles/how-to-tune-up-a-car-engine

and

https://www.2carpros.com/articles/throttle-actuator-service

Please go over these guides and report back.