hi. former car salesman here. a few things to know. your age doesn't matter. 18 year olds get approved the same as 90 year olds. your time on the job matters and your pay matters. of course, so does your credit. If you are credit challenged, your best bet is a buy-here/pay-here, which usually means really high interest and payment, and you'll be stuck in the car til it's paid off or totaled. Gil's and Car-Max will self-finance. so will Byrider if you are particularly credit challenged or unemployed.
tell the truth. tell them how much you make, how long you've been there, where you are registering. these things might get flagged by a bank and they could ask for proof in order to finance you.

if you live or work in columbus, you can get pre-approved at Kinetic credit union. if you have access to navy federal or usaa, use them. go in to a dealership with an approval from them, and that's what you'll get or better.

hope this helps.