If opponent play promising future and i play ttw and opponent play elder dragon how it will be resolved?

Assuming "ttw" is Time Warp: in 1v1, your Time Warp is played first (Promising Future's "next player" plays first), so it resolves before Elder Dragon — but both resolve as part of Promising Future, and neither can be reacted to in that window (FAQ 5673).

Your Time Warp's effect (take a turn after this one, banish it) happens immediately, queueing your extra turn right after the current one. Then Elder Dragon enters the board (ignoring its 12 energy, you still pay its power). Its "When you play me" trigger stays pending and only goes on a new chain after Promising Future finishes resolving — that's when your opponent chooses up to one enemy unit per location and the 1 damage can be answered normally. Elder Dragon's passive also becomes active the moment it enters, so any damage your opponent already had marked on your units becomes lethal in the next cleanup.