Five things I should learn

So I just installed Lubuntu on my old laptop as my first Linux distro to play with.  I have Steam and Half Life, feeling good about breathing life into that old thing.  Now the fun begins, but where do I begin?

What are the top 5 things I should learn and play with in Linux?  Be as broad and vague as you like, it gives me more room to dig in and explore. Being someone who has started to dig into Powershell on the Windows side of life, I am growing less scared of the terminal, so hopefully that can help with suggestions as well. 


mounting partitions?

user access?

dhcpcd ?

I'd agree with those. I learned the most from reinstalling various distros and resizing partitions. Made me appreciate separate /home partition. Depends how you want to use it I guess.

Thanks for the input, looks like some solid places to start, thanks.