>> I'd also like to make money from it somehow.
As a general rule, you can assume that if you Open Source it you will never see any money from it. Perhaps beer money here or there but you won't be quiting your day job.
There are exceptions to this rule but they are exceptions. If you figure out how to get Open Source paid for, that will be more valuable than ERP.
ERP systems are also a terrible idea for Open Source. Your target market is Enterprise (the clue is right there in the name.) Selling to enterprise is a long, complicated, expensive cycle. ERP is at the very extreme of that cycle. ERP projects cost millions to implement, require integrations with hundreds, or thousands, of existing in-house projects, and have full time implementation and maintainence staff.
I strongly recommend you find a single enterprise that is even a little bit interested in talking to you before you go down this road (hint: you wont).
They absolutely do not download and try out ERP level software - that's just not how it works.
I say this not to discourage you. Building something can be it's own reward. But I just want you to be clear on your goals. The odds of anyone ever using this are very very slim. The odds of you making any money at all is near zero as makes no difference.
I'm glad though that you are thinking about the license. Its important to choose a license that matches your goals.