As always with learning something new, things are hard for a while. It's a pain to figure out how to get good resource usage information out of Linux if all you know is Windows. Selenium feels just plain weird if you're used to QTP metaphors. And for a good while it's faster to just install the darn machine by hand rather than try to use an automated system that's probably still a bit picky (read: buggy).
Go cold turkey.
It's easy to cling to the old way of doing things. You may just spend time "maintaining" the QTP tests you have, and figure you'll convert to Selenium later. Or you might install a machine by hand "just this once" rather than use the framework. Don't.
You'll learn by actually using the new thing you've chosen. Only actually doing it for a while will make your new tool or your new process comfortable. It's going to hurt for a while, but it's going to hurt for a lot longer if you don't commit to the new way. So go cold turkey on the old way, and embrace the new.