I bought a 1989 van it won't shift into 2nd and 3rd gear its like its stuck

Do you have a mechanic there that will scan the transmission for you, to be able to determine a possible cause. I would do it for you, but a 30 mile drive might not help matters in this case. Maybe have a free estimate done by a transmission shop.

Is the transmission the only thing it could be?

More then likely with a shift issue on an '89.