What exactly comes after coming to agreement with seller

Good morning BP Community! 

I have several opportunities to snag up a self storage complex and a 18 unit apartment complex on creative financing . Both are almost set in stone.   My problem is coming up soon..  very soon..   Once the sellers accept the offers..  what exactly happens next?  I have no attorney, agent.  I'm dealing strictly with the sellers themselves.  The thoughts that are running through my mind being this close is creating a nightmare in my mind that needs to be calmed.    Thank you!