Can I ask my playing partners for advice, such as what club they hit?

No. During a round you must not:

• ask anyone for advice except your own caddie,
• give advice to anyone in the competition who is playing on the course, or
• touch another player's equipment to find out something that would be advice (such as looking in their bag to see which club they used).

Penalty: the general penalty, two strokes in stroke play (loss of hole in match play).

What isn't advice: public information, such as where the hole is on the green, the location of penalty areas or the rules. Asking or giving advice is also allowed before a round, between rounds, and while play is stopped by the Committee. In partner formats, you may give advice to, and get it from, your partner and your partner's caddie.

Source: Rules of Golf (2023), Rule 10.2a and Definition of Advice.