I am still working on my college applications. Since FAFSA is on a first come, first serve basis to get more aid, am I allowed to submit/file a FAFSA form before applying/submitting an application to at least 1 college?
According to what I’ve learned so far, you can put up to 10 schools in your FAFSA application. And you can also change the schools later if you change your mind.
Can the veterans please confirm or deny? 
I’m just a newbie here. ?
Yes, that is correct. Put any school you might be applying to on the FAFSA. You can always add a school later if you need to.
So I can just list the schools I plan on applying to without submitting applications yet, and still be able to file FAFSA early?
Yes
But you are not going to get a financial aid award until you are accepted. You’re not first in line for institutional FA if you submit FAFSA on October 1, but submit your application in February.
BTW, FEDERAL aid is not first come, first served. Everyone who qualifies gets it. It’s only the school-based aid – “institutional aid” – that MAY be first come, first served. It depends on the college.
Federal work study is federal aid, but the school gets a pot of money that it distributes to aid applicants. At many schools, there isn’t enough FWS money for all who want to work … so sending in your FAFSA early is helpful for increasing chances of getting a FWS award.
I believe that in addition to the limited pot for federal work study, there is also a limited pot for SEOG if you might qualify for that.
So…the early bird catches the worm on both of these.
Also, if you are applying EA, some schools have an early priority filing deadline for financial aid.
And definitely if you are applying ED (doesn’t sound like this OP is) get that financial aid application done.
Some states use FAFSA as the application for their aid, too.
Kentucky Tuition Grant, “Funds are awarded on a first-come, first-served basis.” https://www.kheaa.com/website/kheaa/ktg?main=1