Can I use Punch First when enemy use Rampage on me?
No. Punch First is an [Action] spell, so it can only be played when the Chain is empty (Open State) — while Rampage is on the Chain, the game is in a Closed State and only [Reaction] cards can be played (Rule 334.1.a.1).
Rampage resolves first and the damage is dealt before you'd ever get an Open State window to play Punch First. So you can't use it to save your unit or pump it before the damage lands. Your only responses to Rampage are Reaction-speed cards (or abilities with Reaction).