Best skill/skills to improve first? (openings, etc)

Improving Your Chess - Resources for Beginners and Beyond...

https://www.chess.com/blog/RussBell/improving-your-chess-resources-for-beginners-and-beyond

don't hang pieces and learn enough opening principles that you will not have already lost the game in the first 10 moves.  It is exceedingly difficult to explain to a beginner how they lost on move 8 but the actual game goes on for 30 more moves of a slow and painful to watch rout.  

Choose an opening that keeps your King safe. 

( French Defence is the best choice for that) 

Prioritise the practice of keeping your king as safe as possible.. 

Fianchetto openings are a good way to do that too.. 

Study endgames and don't look at computer analysis.. the computer can show you your blunders but as for strategy only a human can explain that.

I started with puzzles like did nothing else now just YouTube and analyzing the first 10 or so moves of my games win or lose and moves I was stuck on and play out the computer lines to see what the core thought was.

Learn basic opening principles...trying to learn master lines by rota for a beginner is a bit of a waste of time

A: The tactics will be too advanced for you to store in memory and you will quickly forget them

B: If you are playing other beginners you will probably be out of book very early and if you did manage to remember complex variations it would have been a waste of mental energy

Unless you are a junior rated  2200 FIDE and are going to be a GM I would approach openings as suggested initially,I would just concentrate on basic tactics  and the individual weapons of the minor pieces...knight=fork...bishop=pin, skewer  etc...then move onto studying 'combinations'

I have played for nearly 30 years my best years are behind me...but I believe my advice is sound.

blunder prevention > tactics > endgames > openings

Good Positional Chess, Planning & Strategy Books for Beginners and Beyond...

https://www.chess.com/blog/RussBell/introduction-to-positional-chess-planning-strategy

Its ignored because a player starting out is generally an aggressive tactical player....once you have thoroughly mastered tactics then move on too deeper positional play...Petrosian the most positional player you can ever imagine was an attacking aggressive player in his early days!

Edit: Obviously I mean Tigran Petrosian the World Champion

'Positional play' describes something one could learn from reading 'my system' I guess...also Steinitz laid down the bedrock for positional play with his idea's...but don't run before you can walk

Congrats on making it too the champion league by the way

You can try playing a few daily games. This helps with getting better at finding tactics. Daily games allow you to quickly skip through boring positions and completey won or lost games. Yet you can take your time in critical moments to ain-depth analyse a position. This allows you to see checkmates faster.

Hi! My name is Lauren Goodkind and I’m a respected  chess coach and chess YouTuber who helps beginners out : 

https://www.youtube.com/channel/UCP5SPSG_sWSYPjqJYMNwL_Q

Send me one of your games and I'll be happy to analyze the game for free on my YouTube channel. This is a great way to get better.   

Here’s more  ideas to help you get better.  

-I recommend two books for you: “50 Poison Pieces”   and “Queen For A Day: The Girl’s Guide To Chess Mastery.”  Both books are available on Amazon.com.  Both books are endorsed by chess masters!  

-If you are serious about chess, I highly recommend you hiring a chess coach to help you.  

-Also consider all checks and captures on your side and also your opponent’s side. Always as, “If I move here, where is my opponent going to move?”. Do this for every single move!  

-Play with a slow time control, such as G/30 so you have plenty of time to think before every move. 

-Feel free to ask my question on my live chess livestream Youtube channel, every Sunday from 1-2pm PST. 

#10
"tygxc what about positional play? Why is this so commonly ignored?"
++ Positional play is part tactics (setting up for an attack or setting up to prevent the opponent from attacking) and part endgame (setting up for a won endgame or setting up to prevent a lost endgame). There are books on positional play, but they require prior knowledge about tactics and endgames. You can also learn about positional play by studying annotated grandmaster games.

Agree with your post as a whole, except this one. Although open to learning.
French Defence is the best opening for king safety? Based on what criteria?

As long as you castle early and prioritise development, you shouldn't get into too much trouble playing just about any mainstream non-gambit opening from my experience... except in opposite-side-castle pawn storm games.

Steinitz himself warned against castling too early so your opponent can castle opposite and pawn storm...even he was worried, as these plans kind of play themselves for your opponent, if you are not aggressively minded you might not be able to counterattack efficiently...I guess they were the days of the romantic style where all people did was attack and sacrifice and Steinitz wanted a more positional game for his new idea's...nowadays we know we need to breakthrough in the centre to counter against a wing attack I suppose, but if the centre is 'stonewalled' you are kinda stuck against that idea!