Would I be considered as "serving" if I'm in the Army National Guard but haven't been to basic and AIT yet?

If you signed a contract and are attending drills, then you are serving.

Yes. As CW3 Held has said, if you have signed your contract and are attending drills you are considered in service but not deployable yet as you have no actual training. When do you ship out? and where is your BCT? I cannot give any personal advice on BCT as I am shipping July 10th but I can offer words of wisdom.
Try to blend in and not stick out to the Drill Sergeants. Drink lots of water, Remember it is all a mind game, also if a drill sergeant asks you a question just anticipate all your answers to be wrong. As you know nothing. Most importantly EMBRACE THE SUCK! everyone is gonna hate being there. Just do what you are told and keep your mind straight and you'll be good.

So MN ARNG, are you a Red Bull then or have a Red Bull patch?

Yes your accumulating time in service and considered serving but the clock is ticking as your not MOS Qualified. So they will be forced to boot you out at some point if you do not get MOS Qualified (18 months?). However for National Guard once you sign the paperwork at the MEPS you are serving in a Soldier capacity as a State Militiaman. Your just never going to activate to Federal duty unless you get MOS Qualified and they might place other restrictions on you via the local unit.

Also for Infantry there is no real Basic and AIT it is one One Station Unit Training or OSUT, which is one 14 week program. They might split it up for those that want the split option of training but it really is one program. They delineate what would have been BCT and AIT with a Family Day but even still they mix up the course topics so week 1-8 is not all BCT topics and week 9-14 is not all advanced topics.