Because you are the "Primary" engineer for several customers on their client list, bad luck can have you managing several issues/outages at once while colleagues go about a normal day - but as long as you speak up and escalate for assistance, you won't need to work yourself ragged. Colleagues will be pulled to help out. 90% of the time this doesn't apply and everyone tends to get an equal share of the work/projects. There is something for everyone, but if you consider yourself high level 'Tier 2' or 'Tier 3', be prepared to be OK with answering some phones and swapping out some SSDs at customer sites. Your main role is help desk, but you may work about 5 different tickets any given day, while the rest of the day is open for internal/customer projects.
Certain assignments can require after hours work, but this is something no one in IT should shy away from - I can't imagine being in this field and not being okay with that to some extent. Expect to work on a night or weekend once every couple months or so.
You will need to speak up for yourself if you don't see something you need documented or you don't have access to do something you need to - early employment isn't very "guided" here, and training is almost all done informally deskside with other Engineers. However, once you have your first quarterly review, you can set goals and then start setting aside time to work on those goals if the align with the company's objectives.