What is a good Roth Ira to start out with?
Can it be taken automatically each week
from my paycheck?

I have never heard of a weekly payroll deduction, but I do know that almost all custodians offer a monthly automatic checking account withdrawal. Often the monthly option can be started below the usual minimum opening balance, and custodians often waive annual fees in return for the predictable cashflow and long term relationship.

I am not sure what you are asking about with the second question. When you start a Roth retirement investment program you have to make two initial decisions: (1) who will be your custodian and (2) what will be my initial investment. You will find much written on this topic at this site - you can search keywords like "beginner" or "starting".

Or post again and I will try to assist you with more info.