You need a passport and a drivers license. Bringing a birth certificate would be a good idea as well. Insurance is nothing and easy to get. Having insurance doesnt guarantee you anything at DMV.
I would bring the following.
Passport
Drivers License
Birth Certificate
Bill of Sale from previous owner (hand written is fine-must include vin # and both names and be signed)
Scannable Insurance Card (with barcode)
Title of vehicle (Make sure there are no LIENS recorded on the title)
Go to the info desk FIRST.
Tell them you just bought a USED car and need to TITLE and REGISTER it.
They will hand you a YELLOW tax form. DTF-802
They will hand you a White Title and Registration form. MV-82
Or you can print out the above forms (double sided) and fill them out before you go in 