Galactic Legend Events

Once you have all the pre-reqs, you'll start getting GL currency drops from any dark side node (SLKR is dark side, so that's where you get it - if it were a light side GL, it would drop from light side nodes). Once you save up enough of the currency, you can use that to do the event battles - each tier costs more than the last and you have to do most of them multiple times. The earlier tiers reward shards of the GL character - a few of them reward nothing - and the last one rewards ultimate materials.

Thankfully, there's no penalty for failing a battle now - it used to be if you failed a battle you lost your currency and had to farm up enough to try the battle again. 

Once you have unlocked the character, you'll want to gear them up as much as you can. Then you'll work your way through the thematic tiers to the final ultimate tier. You'll need to do that tier repeatedly (10 times? 12 times? I forget how many it is for SLKR) to unlock the GL ultimate ability. 

I'd recommend watching a guide - it used to be to save currency, but now it's just to save time. Griddan on youtube made a great guide for the SLKR unlock - he no longer plays the game but it's still one of the best guides I've seen for SLKR. 

Then you'll want to get on swgoh.gg and have a look at what the character is good at and what team comps are effective for what situations. 

Good luck! Congrats on your first GL!

Get ready for "feint, strike, parry, strike", watch Gridans guide and you'll understand.

As far as how SLKR works, middle ability stuns and removes all opposing buffs, swipe ability dispels debuffs from DS allies and increases your damage output and when you're in the ultimate stance you can't die

Thank you all

There are videos to help.  But the best thing about it now is, you won't lose tickets for losses.  That's huge and definitely a good thing CG has done.  So if you mess up, don't worry about it.

Good luck!