Bachelorette no official bridal party

"My friends however, had mentioned wanting to do something, but haven’t really made any plans. I’m trying to be ok with it since I know there is no obligation to plan anything since I don’t have a formal bridal party"

There is no obligation to plan a bachelorette party or a shower for that matter, even if you did have a bridal party. If your friends have mentioned doing something, then the ball is really in their court. Was the purpose of a luncheon hosted by you In the hopes of motivating them to start planning a trip? If so, IMO that's pushy. The most you can do, if this is brought up to you again, is to say you really need to know asap, otherwise with everything else you and FI have going on it might not be possible on your end. Does it have to be trip like your FI is taking or can it just be a fun night out?

If you were hoping to keep things simple keep in mind that destination bachelorettes, if that's what you have in mind, can be an imposition on people and some of your friends may have issues with finances, the timing, or taking time off. These things are often a far bigger ask than what the bridesmaid role actually involves.

Keep in mind, your friends may have had good intentions but be running into some conflicts or budget concerns at this point. It doesn't necessarily have anything to do with their feelings for you.