No. It is way too hard for someone like me to pay let alone a complete beginner. Perhaps go for a Queens Gambit or 1.e4 to try to get an advantage from the opening. Also in general, fianchetto setups are a little tricky to learn as a beginner so try to play things that don’t have them and once you get to about 1200, then start to learn them
Should I learn the King's Indian Attack?

You can learn whatever you want, but you would be better off knowing opening principles first. That way, you would understand the why of each move.

KIA? At 800? Go for it. Learn the KID/Modern as Black and the KIA/King's Fianchetto Opening as White and make it your repertoire. Then, as soon as you know the basics of what to do in those positions, start playing something new.

it works against EVERYTHING, but requires a lot of theory to master. it just would never suit my style as I hate fianchettos on either side of the board. try it out and see if YOU like it. it sure is convenient when you can use the same setup against a lot of replies.
there's at least ONE really cool KI miniature here by an 800 player who sure wasn't looking like it well into the opening. if you analyze all of your games, you can learn your theory one mistake at a time.
if you do that, you will terrorize other 800s who aren't ready for the strength of your position. heck, you might even surprise some higher rated players with practice.
try it out. that the only REAL way to find out if an opening is FOR YOU.
i tried the advance, exchange (open?), grand prix attack and even the wing gambit against the sicilian and did poorly in ALL of them, but as soon as I found the smith morra, I found my anti-sicilian life partner. it's not as easy to play as it used to be where MOST lines were brutal with Qe2/Rd1/Rc1, but black has learned a lot of strong replies making the theory much more complicated now
test drive it, and get help learning it with analysis and advice if it clicks with you

This is like asking if one should learn to wield a Zweihander vs a Battleaxe
Imagine that you are a medieval warrior preparing for battle. You have the choice of two different weapons: a Zweihander and a Battleaxe. Both weapons are effective in their own ways, but they have different strengths and weaknesses.
Similarly, in the game of chess, you have the choice of different openings, or ways to start the game. Each opening has its own characteristics and can lead to different types of positions on the board. Some openings are more aggressive and tactical, while others are more positional and strategic.
Just as a skilled warrior must choose the right weapon for the job, a chess player must choose the right opening for their particular style and the situation at hand. Just like the Zweihander and the Battleaxe, different chess openings have their own advantages and disadvantages, and the best choice will depend on your goals, strengths, and preferences.
Do what suits you, and play your best. Just remember to always be respectful and keep it civil!
Happy hunting! And remember, on Chess.com we have a mantra: "Battle! Battle! Battle!"

That's why you go for something that has the potential to hurt your opponent instead of some fancy setup that is hard to understand. Classic chess principles will help you more than trying to play passive setups
Alright. I don't really have much to say.
I'm about 700-800 and just wanted to know if the KIA was worth learning or not.
That's about it