How does one begin to search for prospective universities ?

Hi,
I am preparing for GRE and TOEFL for the Fall’19 admissions. I have started learning from Magoosh and have a few questions about the process that goes into admissions, especially the initial phases.

Right now my focus is on prep but as you all know GRE provides the option of submitting 4 Colleges at the end of the test, and the college search is what I am bothered about.

To start off I am not sure if GRE as a standardized test means that I have to stick with my Undergrad degree alone and choose my Grad College based on that. For eg. My Undergrad degree is Computer Science, does that mean I have to take up a course that builds on that - Could I choose a field lets say Environmental Engineering.

My choice for Graduate program will obviously be computer centric, though I still have a lot to research as far as the field and college is concerned. Next, my worry is about the college, where do I start - do I google directly. Where do i search - and how would I know what college suits me. My score is yet to be decided, my Undergrad score plays a role and the fees/cost-of-living is also a factor.

How does one go applying after the colleges have been decided, I know there are guides over SOPs and LORs but a little insight into this matter wold be of big help.

Then come the question of fees, loans and cost of living. Where do I begin, how do i know which place suits me and how do I go about getting a part time job to cover my costs while staying.

If the fees are high which colleges do I apply where the fees are moderate and the college is good. Is there a proceure I could refer to that outlines this for me.

I know I am asking for a lot, but at the moment I need some initial guidance from where I can pick up, following which I could get to the goal.

Please read these articles

What is really best for MS in US