Personally I'm not a video person, so I can't offer you any suggestions on that front - although I expect HellHades has some available. AyumiLove has a pretty good set of instructions as well.

Thanks.  I haven't been over to Ayumilove yet.  My next stop.  

Heya, welcome back. Other than the guides geared towards beginners and progression that you can find on HellHades and AyumiLove, AyumiLove also has patch notes compiled that will list some of the changes that have happened: https://ayumilove.net/raid-shadow-legends-patch-notes-2022/

Sparring Pit, Tavern upgrades, Hydra, Clan Shop and new Doom Tower content are just some of the new things to work through. If you have any specific questions, don't hesitate to ask.

Here's some of my favorite videos on Raid @ClosedPoly 

Do's and Don'ts when starting Raid https://youtu.be/-Aiw3wk-3ik

Beating and farming Dungeon 20 with One Team To Beat Them All Wonderful video on how to build a good team that can farm anything. Answer things like What do I need to build an effective team? What skills and gear are important? What are the strategies and methods to beat each dungeon? https://youtu.be/ziwDFgAPoz8

Building a quality CB team in the first 45 Taking a step back from NM and UNM to show you how to build a Hard/Brutal CB team in your first 45 days playing the game. https://youtu.be/PKc8SHqKkK8

The Basics of Clan Boss What kind of teams you can build and why, how you identify what compositions will work for you. https://www.youtube.com/watch?v=XjsNGq1K55I 

Second video on One Team To Beat Them All This time with totally free champions, no real RNG even (login and campaign pretty much....). Learn more about what skills and builds are important to beat all the level 20 dungeons, as well as more strategies for beating each dungeon. https://youtu.be/iWpsP4K164Q 

How to build a solid speed/nuke team to climb to Silver and Gold Arena https://youtu.be/rfTNsJSPLOM

A few more:

The Basics of Farming to Upgrade Champs https://youtu.be/Ho3yE7kSN6A (edited)

25 tips and tricks to help you progress https://youtu.be/XP7pwWm_iHU

CLEANSE YOUR GEAR! (What do I upgrade?) https://youtu.be/-SxEu5Fdohc 

Thanks everyone.  The forum is as friendly and helpful as I remembered.  

@dthorne   Is there an archive of patches?  I left in late 2020 or early 2021.  

https://ayumilove.net/raid-shadow-legends-patch-notes-2021/

I feel like a kid studying to take final exams.  lol

It's...a lot. I almost didn't link those because so much has happened in the past 3-6 months alone, let alone the past year or more. Some people like having all the information at hand, though. :)

I wouldn't even worry about the patches. Just get in, start playing again!

I think playing is the best idea.   A lot has changed.  I need to change a lot of my heroes and their gear.