My Tranny

[my51chevyrocks]

I'm a newbie at this so let me say that first off. I took my truck out for a short ride around the corner on the 4th of July and had a lot of trouble getting into 3rd and 4th gear. Sometimes I even have trouble getting it into 1st gear, even though it seems like it's in gear, my car won't go. Do you guys have any ideas on what could be the problem? I've driven stick so I know exactly what I'm doing, but with this truck it just seems like it's hard to find the gears. Thanks in advance.