So I have to take math 2r03 online, and I just have applied for LOP.

I made it sent directly to the university (athabasca)..

What happens now? what do I do? I'm so lost on what to do and how to pay for tuition and stuff..

You have to pay for tuition through Athabasca. So, once your letter of permission is approved (you'll get a copy from Mac) you need to go onto Athabasca's site and register as a student which will cost you $113 and is non-refundable. Then you'll register for the Athabasca equivalent of Math 2R03 and then you'll pay it through credit card, cheque or over the phone if I remember right.

Make sure once you've finished the course that the transcript gets sent to McMaster.