if i defy a spell, ravenbloon studend/abandon hall tritggers?

No — neither triggers. A countered spell is never considered "played," so Ravenbloom Student's "when you play a spell" and Abandoned Hall's "when a player plays a spell" both see nothing.

Sequence: your spell is finalized on the chain, your opponent plays Defy, Defy resolves first and counters your spell, so your spell is removed without ever resolving — and a spell only counts as played once it resolves (FAQ #11082).

Worth noting the contrast: if your spell resolves but all its targets have become illegal, it's still considered played and Ravenbloom Student still gets +1 (Rule 359.3.e.10). Countering is different — the spell never gets there.