Okay, let me diagram the sentence for you.

The

• literal no-brain (adjective)
  – would (verb modifier)
  — be (verb)
  — JAKE PAUL (noun, subject)
  then, as a run-on sentence, and exclamation

• Yeah (exclamation

• he (pronoun, subject)

• can (affirmative)

• punch (verb)

• people (noun)

Since you don’t seem to understand American English as commonly spoken, I’ll try to explain. If you’ve had a stroke recently, I understand.

“The literal no brain” means “the action that would be done by someone who has no brains”, as in, very unintelligent or not thinking.

“would be”

“JAKE PAUL YEAh” : to cheer for Jake Paul.

“he can punch people” : in context, someone with no brains would cheer for Jake Paul due to his physical fighting prowess.

Hope that helps.