Transmission or brake problem not sure? Help

Donny, does it act like it is in nuetral when you put it in drive? Or can you feel it engage in gear but feels like something is holding it? I would check the fluid level first off as lots of times they will still go in reverse
when low on fluid but won't build up the pressure to move it forward. If the fluid level checks out I would have some one tranny-wise check it out. I don't see the brakes being the bad guy here cause they probably do it in both directions. Not the greatest on newer models with comp. And junk but start at the basics and go from there. Hope I helped a little, anyway. LOL :)