amazoniangoddess

I agree with other responses to find a paid RA job. I am not sure of your current location within AZ but ASU and U of A have big psych departments. I believe that ASU even has a family studies/human development kind of department separately as well? (If you are looking into clinical, counseling, or developmental route)
1. Like the other posts suggested, directly looking up PIs and their lab webpages will certainly help. I also second emailing the lab manager or at least CCing the lab manager to your email to PI. Profs who are busy doing big research projects (aka have money to hire paid RAs to work on those projects) may often miss your email in the waves of other priority emails.
2. On top of #1, try asking your professors for potential RA opportunities to work for them or their colleagues. I noticed that you are doing online masters so you may not have enough connection with your profs. Still, if there were/are any classes that your did well in and received good feedback on your course work, I don’t see any harm for reaching out to them for any relevant advice, tips, consulting, etc.
3. Use job search portals. I found indeed & higheredjobs to have the best relevant listings of research positions. Also, each university/college has its own job listing page somewhere. Although it lists all sorts of job positions open in the university/college community, you should be able to sort via advanced search to look up research opportunities only.
Hope this helps and good luck!

In the very least, you may be able to assist with participant screening and administering questionnaires over phone after work. Look up a psychology research lab that’s investigating a topic of your personal interest, then reach out explaining your situation and suggest the possibility for you to help with participant screening and questionnaires over phone in the evenings.

I would suggest cold emailing a laboratory manager (or similar) instead of the PI themselves.  We often know more about the day to day operations of the research and may have the authority to make these decisions.  I know that any email of the sort my PI sees gets forwarded to me anyway.

For those looking for paid opportunities: indeed.com, type in “psychology research” in the keywords and your city/state. Professors with active labs (especially around this time) are known for always posting on there. Also, before applying to any advertised position: Make a competitive cover letter + CV that is in academic format and obtain feedback on those items from a supervisor or colleague.
I found my most recent clinical research coordinator job through there at a very prestigious AMC after my 2nd round of applications. The opportunity allowed me to get clinical research experience and numerous pubs/presentations as well as excellent mentorship from the leaders in my specific field prior to applying last year (for the 3rd time).
If you truly cannot quit your current place of work for financial reasons, cold e-mailing PIs for opportunities about volunteer options (esp. emphasizing your availability in the weekends/evenings) should get you some leads. Best of luck to you.

I only used the Kaplan review book and scored in the 93rd percentile. I also agree that you should delve into an intro psych text book, particularly in the area of biological psychology and statisics.
What's also important to do is take the practice test ets provides early, and thoroughly research and write up any topics covered in there (even as just multiple choice options). The Kaplan/Princeton review practice tests will give you inflated marks and will be much easier in comparison.
Play to your strengths and make sure you know what you know. For example I made sure I did well in clinical and developmental sections as I applied for child clinical programs. As such, my 75th percentile in biological psych didn't matter as much.
Also remember that it's nearly impossible to have exhaustive knowledge of the test. Even when you write it you'll come across some things you've never heard before. Stay calm and know that raw score doesn't matter; it's just percentile. I probably only got a 70% on the test but still came out really well overall.
best of luck!

There are some programs in Psychology that do offer a partially-funded or fully funded MA degree. Some programs I'm aware of are:

College of William and Mary (Williamsburg, VA)

Indiana State University (Terre Haute, IN)
Villanova University (Near Philadelphia, PA)
Wake Forest University (Salem, NC)

University of the Pacific (Stockton, CA)

I only studied with Princeton Review and got over 80th percentile. Keep in mind I do have a double major in Psychology and Neuroscience. I found that the Princeton book did not cover enough biological psych and if I didn’t have my Neuro degree I wouldn’t have known quite a bit. 
I would take a practice test in one of the books you have, and determine which area you need to focus on the most! It’s great that you’re starting early in the year. 

if a friend has a Psych 101 text book, I'd reference that along with your studying!

I think I had the Kaplan review book, and I didn't get all the way through it because it covered so much of what my courses did, so I think that's a good resource. You should also look up the typical percentages that each subsection takes up and be sure to focus on whichever section(s) gives you the hardest time in practice exams. I'm not sure if schools weigh your score by area or only care about the overall score, but the report does show all of that. As goes for the regular GRE, it's always best to do multiple practice exams to give you a feel for it.