What should I do?

I wouldn't change my plans. I would go on my trip and then join the gym. Otherwise you'll be interrupting your workouts right in the middle, then going on a trip, then trying to get back into a pattern again. If she really likes you, she won't mind waiting.

I have questions.

How young is she? You’re 31-35.
She wants to join a gym with you but you will be paying the fees? Will she be sharing the cost of the membership or just be your guest?
Is this a trip you have been planning and saving for and looking forward to?
Did you have intentions of joining a gym before she said something about it? Is it something you have been wanting to do?

I’ll be honest. Based on your post, I’m getting the vibe that she’s using your interest in her to get a free pass to a gym.

If this has potential to be more than a friendship, postpone the trip and spend some time one on one with her at the gym. By then she may even want to join you on the trip.

Tell her about your trip

Ask her not us

Can she join the gym on her own and then you join when you come back from the trip?, or is she expecting to go on your membership and have you pay?

Why do you have to join together?

looks likew gym is the best idea sad 6 month fee, while keep saving for the trip

You should join the gym then take on the trip with you.

Join the gym and skip the trip silly!

You should ask her out immediately and sort out whether or not there is a possibility of a relationship with her. That is what you need to know before you make a decision on what you should do.

Work out at home. Ask mom to prepare tea when you invite her over for a friendly tea with Bubu & family.

If she’s already a member, ask her to take you as a visitor. Of course your goal is to get another date with her somewhere else.

Be honest .🤷‍♀️

Go on the trip then join the gym

tell her to join on her own