If it was me I would start with checking the plugs, make sure the wires on the plugs were on. Change the fuel filter. start with the basics, maybe a tune up. My wife was trying to go up a hill in an old country road and the van did not just move right, after we left a friends house. To make a long story short she left the parking brake on. you might have a sticky wheel cylinder just or brake hardware.

You can do a compression test on the cylinders other than that I will leave more expert advise from the other guys here.

"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my sweet ride." -Amen

56 Chevy 3100