I would like to find those I served with at Ft Hood in 1980, how would I go about that?

If you still have an "I love me book" of all your Army documents, many times you can find group orders for TDY, Awards, deployments with names of those you served with at that time. Then search out those names, asking not just to reconnect with them, but do they have an old company roster, group orders, ect.

Depends on the Unit. I was assigned to the 27 Maint. Company at the time.

One suggestion: the Sandboxx app