Need help starting a script blueprint

hello i am a new developer and i have some knowledge of scripting and would like to give it a try. i need a little help choosing the right nodes and the order to place them.if anyone can help me with this i would greatly appreciate the help. thank you to anyone who helps me and for your time. i would like to create a blueprint that does the following:
3 ammo pools that are separate, and have the current and max ammo values.
store extra ammo for 1 of the 3 ammo pools (I was thinking of using a variable).
increment extra ammo with a trigger box.
decrement ammo by pressing a fire button.
switch between the ammo types (I would like to try a state machine).
stop firing when out of ammo.
Print ammo values in each pool to screen.