Good afternoon.
Well, Arduino always sends compilation errors whichever errors it encounters ...
Check those points:
* Do you have all the needed libraries installed and updated ?
* do you use the proper Port ?

Have you tried using Xiaoo boards ? much smaller and easier to use. Those are ones I use wjthout any problems.

I can't give you a precise help because I am not a Arduino specialist and do not have your whole set here in front of me.
This kind of trouble can so easily be avoided by asking Bert (aka Brutus) for a completely functional set, Arduino is so poor in help that I finally gave up trying with those.

When you eventually will be successful with your Arduino set, you have to make a solenoid set. This needs a lathe and how to use it properly !

My advice: ask Bert !

Have a good day