1997 Ford Escort )please help thank you

I have a 1997 ford escort, just bought it, when I left the previous owner house approxamatley 3 blocks it just stop moving I hit the gas, nothing down shifted nothing (automatic) I pull over put it in park waited 2-3 mins, put it in drive it went. Drove another 2 miles it was fine, let the car sit for 3 days got in it started it put it in reverse than foward for about 2-3 mins, nothing was still running but wouldnt go forward or reverse, felt it kick in to drive and reverse. Very concerned for this is my only car and im a little brain dead whn it comes to cars. Please any advice would help thank you, scott