It is probably best that you actually do some thinking beforehand before you go out with your new fishing SUP board. For starters, think about the fishing gear that you are going to bring. As was alluded to, you want to be careful to not bring too much.
Sure, you will want a good variety of tackle and fishing rods to play with but you should also limit what you take. Remember, you will need to keep track of all the gear you end up taking. On another note, plan out where you will enter and exit the water. The same place you launch may not work too well when you need to get out of the water.