To OP:
meditation can be an amazingly rewarding practice. It is not a “holiday” for the brain but rather proven steps and exercises. to better understand our own minds and to develop more productive actions. We usually don’t learn that in our western public schools.
It can result in life changing paradigm shifts.
it is important to have good instructor to guide you and to answer the questions that will come from your experiences.
if you want to prepare for a retreat or begin a practice “ Tergar Thailand” can be a helpful start. The Joy of Living classes are very good and designed for our westernpreconceptions. https://www.tergarasia.org/thailand/
”mindful meditation” is secular and you do not have to become a Buddhist to reap the benefits.
Personally I would suggest some instruction and a few months practice before a long retreat to maximize the experience.
enjoy.