which plug (obd1 or 2) do i have?

I would like to tune my car with lt1 edit or tunercats. which one is prefered? I also will need to get a cable. How do I know which plug to get(for under the dash)? It is a 95 formula. thanks.

My buddy has a '95 - it's OBDI with an OBDII (16 pin) DLC connector.