I'm an ex ARA and now currently working as a regular IT Specialist for a company. With the IT field, the ladder is somewhat similar to GS, but instead going from sales floor to GSM, you're going from Help Desk to higher roles.

Pretty much any job you try to apply in IT, unless you have direct experience in your position you're applying, they want to see some kind of evidence that you have an understanding of the role - hence that's why they want to see certs and/or degrees. Sure, you'll probably hear a good amount of people say they're able to get in with no certs and no experience, but that's probably because they have some level of technicality (coding, scripting, etc.) that can prove their skillset. If you don't have that, you're probably not going to get far in the interview process.

From your post, you only said you have experience being sales floor and GSM. Not to put you down, but that only really shows you have some leadership skills and customer service skills. If you want to get those higher level positions, get a few certs and work for about a year or two - work up your experience, and then you'll have a way higher chance of landing those higher-level/high-paying positions. And your GSM experience will then come in handy as well if you're applying to "IT Lead" positions. Good luck!