|First, if you wish to share two separate internet connections, you're going to need a dual WAN router.|
Once you buy one, then you'll need to read through the manual to configure it.
Once you've done that, if you still have questions, come back in here and post them.
Just FYI, without a dual WAN router, you can't do what you're asking.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.