I have 97 bravada has all gears except 1st also will not shift on it's own I can manually shift it has 2 3 drive and reverse please anyone have any ideas

First thing is check trans fluid level. Check with engine running, warmed up, on a level surface, in "PARK" (not a bad idea to perform a full range cycle of the shifter lever with engine running before checking fluid level, giving the vehicle a moment for each position of the shifter- ie shift from park to reverse, wait a moment, shift from reverse to neutral, wait a moment, neutral to drive, moment, etc down through first, then back up to park in the same fashion. Then do the dipstick check) Low fluid will affect transmission function so correct any deficiency.
Second thing is check for trouble codes. Engine light or trans light on or flashing indicates a diagnostic code is set. Pursue accordingly.
It is possible that your transmission may be in first stages of total failure.......
................BUT................
Before you resign yourself to that extreme, there is one more thing to try. There is a pattern on these vehicles where a component inside the ignition switch develops an issue which causes the car to start out in 2nd or 3rd gear when you try to drive it. Every thing else regarding the switches function works perfectly an it is apparently doing everything it is supposed to do. Feels like it should when you turn it, etc.
The only way to determine if this is the problem is to put a new switch in the car and see what happens. Note that we are not talking about the part you put the key into, sometimes called the lock cylinder. This is the electrical switch that has all the wires and electrical connectors. It is behind the lock cylinder and you have to "skin" off the covers on the steering column to get at it. Not the most expensive thing to replace, but they don't give them away either. Neighborhood of $75-$80 if I remember. One angle of approach on this would be to purchase from a parts store with a liberal return policy. If it doesn't fix the shift problem, take it back ("it's over my head and decided not to try it" excuse). There are some Youtubes and other forums that you can find details on the replacement procedure. It's kinda fiddley but do-able. There is one screw that may give you some trouble. It's a very tiny Torx socket head screw that holds part of the switch on the steering column. T-5 or T-3 Torx bit or something like that, and that proper bit can be a little hard to find. I have used a tiny hex bit (Allen wrench) in a pinch to turn these out but had to tap on it a little to set it into the screw. The screw is not normally tightened too much and will come out if you can get a little bit of bite onto it. Be mindful of that when assembling. Also it's probably a good idea to not crank down any of the fasteners until you've established that this did/n't fix the problem. Just set all fasteners lightly enough that things don't rattle around(much). Tightening beyond that point can leave marks on the part making it apparent that you installed it, and may complicate the return process if you go there. On that point it also helps to keep your hands clean so you don't smear up the new switch....and keep the box put up where you don't mess that up. If somebody says "looks like it was installed", reply that it was like that when you got it. Hopefully that won't be an issue and this fixes things. If that's the case, remember to tighten everything down to make the installation secure.