Need help understanding insurance

So I am going to work for UHG/Optum in Arizona as a medical assistant starting at 17 an hour(26k salary) and in a year it’ll be 20 an hour(~30k salary). I know I can get insurance through my employer but I have no idea which one or know what it all means between the four options I have. My boyfriend also just turned 21 so his AZ ACCHS(medicaid insurance?) just basically got shut off, he makes around 26k annually. The other complication is that I deliver in April but that is 100% covered by my dads insurance (BCBS of ohio) only because I am still in school and can be covered until I am I believe 21/24(unsure). I am looking to get insurance because you need it for a baby after 1 month, also because my boyfriend needs his wisdom teeth out and I’d like him to have good coverage but he also just should be on an insurance in case anything ever happens. Which option should I select with UHG based on my circumstances and should I even go through my employer or would I get better benefits as far as oral surgery somewhere else. Just looking to have good coverage for that specifically only for this year.