Need Advice - Application (Can't Remember Stuff)

When it comes to employment, most companies will want you to be at least within the month for starting and ending dates - like 5/13-9/14 - that sort of thing. And they will need at least a company name and phone number to verify your employment.

Regarding prior non-driving positions for people looking to get into the industry, do they contact your actual bosses/direct supervisors from your previous jobs? Or do you just give them a number for Human Resources and someone from HR verifies that you worked there?

I've moved a few times and worked a few different places but, I'm terrible with months. Luckily, I've had the same bank account forever and have filed taxes yearly. I got all my tax transcripts since I began working (I'm only 24 so not a lot of history.) And I got all my bank statements since I've had the account at 18 so I can cross reference direct deposits, check deposits, and withdrawals in large sums for rent with the tax transcripts. Seems tedious, worth it though.