I ask a lot of questions of those who do know parts of it. If I hear something I don't know or understand in a meeting I always write it down and research it later.
In a dev environment, I poke at things. Back up that config file, tweak some things, see what happens. Take stuff apart, put it back together. Revert things to put it back when I'm done. It's the dev environment, it's supposed to be shaken up and messed with.
With code, I find a good debugger for whatever new platform I'm trying to get into. Put some break points into interesting spots, step into to the function, step into, step into. See what's really happening. Inspect all the things. How does this thing actually tick? Watch it spin.
When an employer offers any time for training, I take it. I try and get as much out of it as I can. My employer offers some continuing education reimbursement. I use it.
Make time in your work schedule to spend some time learning every week. Make yourself a 30 minute or 1 hour recurring meeting with only you.