Start with the basics
A blind player has not looked at their cards; a seen player has viewed them. How these states affect a turn depends on the rules being followed.
Put it into practice
Watch a demonstration and note when a player may view their cards. Compare the labels in the app to the explanation for that version rather than relying on a similar-looking interface.
Before your next session
Ask about unfamiliar controls before joining a session. A practice game is a useful place to learn vocabulary without rushing. No label or play style guarantees a result.