Hello everyone! I’ve done some searching for other threads on first-time buying and have gained some new insights but I would really appreciate any insight, tips or useful info you can offer. 
Quick Background: My current car has been going downhill for a little while, but it’s finally reached a point where any more major repairs don’t make sense for what it’s worth (’98 Accord, 271K miles, terrible paint, engine seals leaking, etc, etc). I’d had a goal in mind of buying a brand-new or not-so-old used car by the end of this year, but after just plunking $300 more in repairs, I’d like to accelerate that plan to sometime around Spring/Summer. I'm not looking for anything fancy, just not anything old, my time of beater cars is over. I'm not tied to any car in particular, but was thinking something along the lines of a Honda Fit, Kia Soul, Ford Focus/Fusion, etc.
My utilization on my cards is currently very high, around 80%, a downside of Christmas + textbooks (no financial aid here) + car repairs all in quick succesion. My aim right now is, of course, to bring them all down asap, in addition to continuing to build my down payment savings. As far as that goes, I will have $2,000 for sure, hoping to have $4,000 by the time I’m ready to make a move. I saw the drop in my score the past 2 statements as I wasn't able to pay down enough as I intended, so I know they're not the greatest right now.
Buying for the first time I know tends to favor having a co-signer, but that isn’t an option for me. My mom has a current auto-loan out but has also been semi-recently been laid off, so she’s having her own financial up & downs, which without knowing her current score, I’m sure have hurt her a bit. My SO has no credit history to speak of, but I’ve finally been able to convince him to set aside part of his tax refund to get a secured card. So I’m getting him on the right path but useless to me for this, ha.
I have no previous installment loans or student loans. My sister would almost definitely add me as an authorized user to her Barclaycard (forgot the limit, I beleive $1,5-2000) if I asked, but I'm not sure if that would help or hurt, doing it just a few months before.
Cards: $500 limit Cap One QS | $500 limit Verve |$410 limit Open Sky Secured | Fingerhut $700 limit (shows as retail card on my Exp, not sure it it’s truly seen as a CC to most)
Oldest Account: 1 year, 9 months
Average Age of Accounts: 10 months
FAKOs: CK 584 TU & 616 EQ | Credit Sesame 584 | Credit.com 659 | Cap One CT: 603
FICO (Experian) Score 8: 636
No negative accounts on my report nor any late payments. I make around $22,000 a year and currently live with my SO’s family. My rent is extremely negligible nor am I on their lease. I understand saying you pay little to no rent is actually a negative for buying a car..? I would think just saying I pay more than I do would be the easy solution, but then I obviously don’t make a whole lot, and then that would make me seem like I have less income to go towards my payment.
Thank you for reading this far! I’m looking for any type of helpful information; Aside from lowering my utilization, are there any other smart moves I should make that can have a positive impact on my score? I’m assuming getting a new card, while helping to lower my util., would be a bad idea a few months out from applying for financing..? I am currently in school part-time, do any automakers offer anything geared towards students, any little thing would be helpful. Any particularl pitfalls to avoid?
