You’ll have to transfer either using an external HDD / SSD via USB-C, or you can transfer wirelessly using something like Syncthing or KDE Connect.

You get points from purchasing it, but they can’t be used to buy games. They’re just cosmetic, you can buy avatars, backgrounds, avatar frames, emoticons, etc. Anything in the points shop.

You can also claim a profile bundle, and if you get the 1TB there’s also an exclusive startup movie and keyboard theme. Make sure when you get the Steam Deck you log into the account you want to claim those on as you can only claim them once. (You claim it when you have the Steam Deck in your hands, it shouldn’t matter which account purchases it).

Based on the games you have in your library you might like some of these,

Jet Set Radio

Bomb Rush Cyberfunk

Dragon Ball

Teenage Mutant Ninja Turtles

Street Fighter

Soulcalibur

Mortal Kombat

Injustice

My Hero One’s Justice

Naruto

Brawlhalla

Persona

Yakuza

Ys

Tales of

The Legend of Heroes

Octopath Traveler

Chrono Trigger

Legend of Mana

Secret of Mana

Trials of Mana

Star Ocean

Phantasy Star

Final Fantasy

Castlevania

Mega Man

Witcher

Elder Scrolls

Fallout

There’s a free Steam game called ‘Aperture Desk Job’ which teaches you about the Steam Deck.

Proton lets you play Windows games on Linux.

The easiest way to mod games on Steam is through the Workshop. You can select a game, scroll down to the game info tab and there should be a workshop tab, if not it might be in the in-game menu. You can also go to desktop mode and under the community tab you can select workshop.

To enter desktop mode press the Steam button, go to power, switch to desktop. You can also hold the power button down and the same menu will open and you can switch to desktop there.