Learn Turkish: Onun görüşüne göre herkes tembel. - According to his view, everyone is lazy.

Let's break it down! görüş means "view". To say "his view", we add the possessive suffix -ü to match onun, making görüşü. Because the postposition göre (according to) always requires the dative case, we need to add the suffix -e. Whenever we add a case suffix right after a third-person possessive suffix, Turkish requires the buffer letter -n-. Putting it all together: görüş + ü + n + e.

Does the word görüş come from the verb görmek (to see)?

Exactly! The verb root gör- (see) gets the suffix -üş, which turns it into a noun describing the way an action is done. So a "way of seeing" naturally translates to a "view" or "opinion".

Since herkes means multiple people, why isn't tembel pluralized as tembeller?

Just like in English where we say "everyone is lazy" (not "are"), the Turkish word herkes (everyone) acts as a grammatically singular subject. Therefore, the adjective tembel stays in its simple, singular form.

Could I drop the word onun and just start the sentence with Görüşüne göre?