88 Broncos
 

Starts , warms up and dies then won’t star again. Need help on what should I check first.

The 2 main things to check would be fuel and spark.

There could be an electrical problem that could influence fuel control.
Spark is entirely , mostly an electrical/ignition problem..

If you are planning on doing some of your own work, you might invest in a spray can of carb and choke cleaner. Starting fluid can be used , but I hesitate to suggest it's use because most people use too much and that can cause internal engine damage
Carb and choke cleaner is closer to gasoline and when a shot or two is sprayed into the air cleaner it can tell us if there is a no fuel supply condition.
Spark is usually checked by removing one of the spark plug wires from the plug and inserting a small screwdriver into the wire end and placing the screwdriver shaft about 1/4 in away from any metal on the engine and cranking the engine to see if spark jumps from the screwdriver shaft to the engine when the engine is being cranked over to start.
Just make sure you are not holding the screwdriver, could be 20,000 volts there and that would certainly get your attention.
I hope I explained this well enough so you don't get hurt trying this.

This is very vague. You need to provide more information. Anything provided would be just guessing.

Since it won't cost me anything, I'll take a guess !!

One of 2 possibilities,

Either the ign coil is opening up as it gets hot or the pick up coil in the distributor is opening up when it gets warm.

I doubt it is fuel related.
All you need to do is check for spark when it won't restart and either you will have spark or will not and we can go from there.