If in doubt about my ticket/membership status. for entry to the lounge, when I check in or drop by bag at the baggage drop-off desk I always ask "do I need an invitation for the lounge". In some airports you do... so it;s not an unusual thing to ask and they'll hand you an invitation if you qualify and if they are needed, or tell you if you don't qualify on your particular membership/flight combination.

The only other thing you have to be aware of is the advice already given by someone else on this thread that the airline will always direct you to their own lounge or contracted lounge - which may not be the best one that you have access to. So you should research available lounges online - find out where they are and either ask ahead or try.