Job offer contingent on passing CompTIA Net+ and security clearance

So the network+, while difficult, is within my control. What is not within my control is whether I get clearance. This would be Tier 1 tech support through a temp agency. What level of clearance would that be and what would my likelihood of getting cleared be?

I am definitely not a perfect person. I have a 6-year-old misdemeanor (which I served probation for and have a good mitigating reason) and a 540 credit score (because I have lived on SSDI for a number of years) and schizophrenia (which is well medicated and my therapist said she would vouch for my stability). I mainly want this job for increasing my resume. I don’t have much to speak of in terms of resume qualifications other than 10 years of food delivery and customer service.

The background investigation is either a medium risk public trust or a secret clearance for most entry level IT contractors in the federal world. The background investigation could be more thorough depending on the contract.