First time mom, curious as to how far ahead should you send out baby shower invitations/get a guest…

First time mom, curious as to how far ahead should you send out baby shower invitations/get a guest list together? I want to have my baby shower at end of February when I'm 30 weeks. I'm about to start back nursing school & I don't know when I'll have time to get all of it together (in my 23rd week now)