All
Entire, Everything
noun, の adjective
This has a little hiragana attached to it but nothing that suggests it's a verb or an adjective. That means you can assume this word has the same meaning as its parent kanji.
すべて
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you:
You have to remember the すべ part, which is an admittedly difficult sound to remember. You have to think of the concept of all or entire. When you think of that concept, think of someone's entire fortune. All their money. You want to get all of Beth's money, so you sue Beth (すべ) for all she has.
全てうまく行きました。
Everything went smoothly.
申しわけございませんが、げんざい全てのおせきがうまっているじょうきょうでして...。
I am sorry, but all the seats are fully occupied at the moment, so...
僕が先だよ。ウィキペディアが僕の宿題を全て真似したんだ。
I was the first to do it. Wikipedia copied my entire homework assignment afterwards.