Linux

I do not know what sort of power management software exists by default on Ubuntu, but for laptop use I would strongly recommend getting a power management package like TLP to configure power profile settings for your laptop when on battery and on charge. It can greatly improve battery performance. Some alternatives like auto-cpufreq and powertop exist, but I have tried all 3 and found that TLP worked the best for me.

Here's a good reference: https://linuxjourney.com/

Set up btrfs and timeshift. You never know when you need that big undo button.

I think the two "major tips" that I can give you are simply

1- Package manager is your best friend.

2- Figure out the "know-hows" of Linux (i.e who "is responsible" for the video card, who deals with the cpu, how do i configure my sound card, how do i configure my video card, etc.).

Master those two tips and you can call yourself an average linux user.

Most distros are good enough without much tweaking. in terms of commands...some more advanced stuff...

start poking around proc to see what linux gives you, without needing a program to get it!

@Classy Give a try trade-free linux distro TROMjaro.

Honestly, youtube "basic bash tutorial" and watch/follow along with a video or two. Helped me a bunch.

Unless you are looking to work on shared systems/servers as sysadmin or other jobs, explore shells like zsh or fish and customise them rather than stick to bash. A lot more user friendly and accessible advanced features. Helps with learning a lot. Zsh is compatible with bash but fish isn't. So choose based on what your goal with learning shell is.

If you are sticking with debian based distros, try apt and synaptic(GUI) to install your software. At some point you might also need to install tar archives. Don't get worried as most guides should be easy to follow.

Books, books, books! O'Reilly publishing is your best friend. Search engines are next. And finally, Youtube.

Two tips:

I have not tried running WINE yet but I plan on doing so soon.

Steam "just works" on Linux, you can install it via flatpak (which I use) or from their deb repo. It includes "Proton", which is a fancy bundle of wine and some extra open source valve sauce to make it nice and easy to use. Any game that runs on the steam deck also runs on Linux via proton, and there's no messing around at all. It looks and feels just like steam on Windows, and thousands of games just work with no setup or config beyond clicking the big blue and green buttons to install and run. Not EVERY games works, but tons do. I'd heavily recommend this over raw wine to a beginner.

The second tip is not to ask what you can do on Linux. The answer, to a first approximation, is that you can do everything on Linux that you can do on Windows or OSX. I daily drive all three, and mostly do the same stuff on them. Instead, ask YOURSELF what you WANT to do on Linux. Then Google and ask us HOW to do it... or what the nearest approximation is if the precise thing you want to do doesn't work on Linux.

Start off with Bottles if Wine is too hard. Wine is a cmd line application while Bottles is Wine with a GUI making it easy to manage Wine.

Also, it is wise to try and have a different wine bottle (aka prefix) for each windows application you install and run.

Also Linux Mint is a distro that comes with Cinnamon pre-installed as long you download the Cinnamon option which is a fork of Ubuntu.

Tip? It is just a means to an end.

Personally, I think Arch Linux is the best way to learn the command line. It throws you off the deep end and you have to learn things like how to navigate the file system, how to edit files with the command line, and useful tools like partition editors and package managers. If you're serious about learning command line, just go install Arch Linux from the command line.

Otherwise, I think you can learn a lot about the Gui on Ubuntu by just using it. You can run some windows-only apps with WINE or you can start learning how to use Linux-native apps like GIMP, Libre Office, and other various Flatpaks.