Can paying my mortgage loan on time help my credit score...and other financial questions...?

ok...so last time I checked my credit score (about four months ago) it was 609. I do have a few debts from my past. All the debt I owe adds up to $1500.00. I plan to pay this off soon, but just haven't got the money yet. Everything I owe dates from two years ago and later. nothing recent. Well, I got a loan for my trailer with a co-signer two months ago. Have made my payments ontime. Well, will this help my credit score at all? How long will it take to help out? I just recently wrecked my car and I got $2000 for it totaled. I need a good reliable car so I can go back to work. I need a car loan BADLY!!! Not much maybe 9-10K at the most but definitely willing to take even lower than that! I would go as low at $4500-$5000. I have two kids and really can't get some cheap car that'll break down next month. How can I get an auto loan with a credit score of 609. Do you figure it's gone up any since four months ago? Please help!!! I am 21 and should know more about this stuff, but I have no clue about the whole credit and loans thing. Any info would be EXTREMELY helpful! Thanks again! Take care everyone and God bless!