What collections should I pay off first to make the biggest impact on my credit positively?

[Pabudo22]

It's embarrassing to say but over the years I've been pretty irresponsible, I made a lot of mistakes.

now I'm I'm finally in a position to finally pay some or all of it off

 Today I was rejected by my first apartment application ever because my credit was off by 10 points. I've got some money I was going to use to get the appt. But now I won't be using it for that, the best thing I can do is use it to start fixing my situation 

I have a few things in collections-

There are some tires/installation I financed 4 years ago. Probably owe about $500 wherever that debt is

There is an unpaid US cellular account I owe $375 on

pretty sure I have an old t mobile account in collections as well. Not sure what the story is there.

I've got 4 traffic light tickets from 4 years back that is $850

There are two major banks that I had checking accounts in that are in collections somewhere with around -$50 each

A gym membership with $100+ owed

This is all from the last 6 years.

[FicoMike0]

To get a full look at where you are, you can get you reports from all three bureaus at annualcreditreport.com. This will not give you scores. 

A simplest starting point would be to sign up for the free subscription here at myfico. They have a phone app that works well for me. This gives you your Equifax fico8 score and access to your Equifax report, in summary form, which is easy to use. You can get similar experian data free from experian.com.

Most data drops off your credit reports after 7 years. If you want to prioritize what to deal with first, best to go after the most recent and the smallest amounts first.

[FicoMike0]

Your bad bank accounts are likely on your Chex systems or early warning systems reports. These are where banks check before deciding if they'll open a deposit account for you. Sort of the bank blacklist.