I know that I'm biased, but TBH 8 or 9 years ago I was in the same boat as you. I'm not sure if I'd have ever bothered getting to know Linux if it wasn't for Webmin when I first started using TurnKey. But I'm sooo glad I did get to know Linux, it's all I use now!

After using Webmin for a while I got a bit of a feel for Linux and started playing on the commandline a bit more. After mucking around on test servers and getting a bit of confidence, I've discovered the joy of commandline! Once you wrap your head around it, it is so much more powerful and so much easier!

It makes things like following tutorials so quick and easy! You just copy/paste the commands and stuff just works (ok, not always, but mostly). I find following tutorials in a GUI environment so painful, and I often find myself on a step that just doesn't make sense, or I can't find the thing they're referring to. I know video tutorials make working with a GUI much easier, but I'm still a big fan of commandline.

Anyway, enough evangelism from me! :)

To answer your question, you can install packages via apt from within Webmin. I think it's called "software management" or "software packages" of something like that. Have a dig in the menus and you should find it. If you get stuck, please post back and I'll have a proper look for you. Please also keep in mind that you'll need to install the proftpd server software itself too. Installing the Webmin package just gives you the web UI, not the underlaying commandline software.

Or if you want to try installing the commandline way, you could just log in via SSH and run:

apt-get update
apt-get install webmin-proftpd proftpd

Another option is Webshell (on port 12320) although personally I prefer a proper SSH client as I find copy/paste flaky in Webshell but YMMV.

Re upgrading Webmin to the latest version; do you have a reason why you need to do that? Is something not working? As a general rule, that's not how Linux works. Stability is preferred over the latest shiny version. Usually if things aren't broken (e.g. something not working, a security issue or a missing deal-breaker feature) then the tried and tested version is preferable.

Having said that, in a perfect world we would probably update Webmin more often.

Anyway, currently the only way to upgrade to the latest upstream (i.e. Webmin themselves) version is to get your hands really dirty on the commandline. I won't go into it here, but I'm sure you can find instructions on the Webmin website. If you keep in mind that TurnKey is Debian under the hood, you should be good.

If you want to go that route; personally, I'd be inclined to muck around in a test VM and document as you go. Then you can be fearless as if/when you break something, you can just rinse and repeat.

FWIW we are currently working on the next TurnKey release. One of the components of that will be upgrading the Webmin packages to the latest upstream release (and testing thoroughly). Actually the packages we are testing can be found in my dev-testing repo. If you're at all inclined, please feel free to have a play with them and help testing. Although I strongly recommend that you don't add that repo to a production server! Once we've finished testing they will be added to the main TurnKey repos. You will then be able to install them with:

apt-get update
apt-get upgrade

Regardless of which way you go, please give us some feedback. We love feedback, even when it's not good - just so long as it's not too ugly! :)