Transferring from community college to University

Hi everyone! So i've been thinking a lot about this and it's new to me. I always thought I would go to a straight 4 yr college that not expensive and I didnt want to be in dorms. I am considering community college and transferring. Many say it saves money and it saves you time for thinking about your future.

- My biggest question how does transferring look like?

- Are there different requirements for transferring for a top school?

- What should I be doing as a highschool senior.

I come from a poor ish family. I have like 10 family members in one small house. I am going to pay for colllege on my own so it's gonna be hard. This one of the biggest reason I'm considering community.

- When transferring am I able to get a pell grant when transferring to my dream college even though I went to community?