Pretty much as the others have said.
I've been doing this for a while now. My instructor competes/teaches Tae Kwan Do, Kick boxing (korean style with TKD feel) and self defence. His brother focuses on the boxing only.
At the school I attend, the taster/trial is basically 3/4 of a beginners class. This means they get the feel of the class.
The beginners classes (10-8 kup) focus on the basics, the correctness of technique, self defense and fitness. There's forms, pad work with partners and also non-contact exercises (such as one partner jabbing to the head, the other blocking or deflecting) where the object is getting the technique right rather than hitting to opponent fast or hard.
Kit includes bag mitts and soft shoes.
You'll find that as you do this your muscles will start out weak (wobbly with a leg in the air, core muscles etc) but by the end of it you will have a very good balance, good core strength and fitness.
This is 2-3 times a week.
Intermediate classes (7-4 kup) the emphasis changes. This is the beginning of the journey to the ring. The focus is technique but also on sparring, additional fitness that ramps up. We also get additional boxing classes.
My kit now includes feet guards, shin pads, full sparring gloves, head shield, groin guard and gum shield.
We now do partial and full round sparring. Although the idea is to, again, practice technique without killing each other.
This is 3-4 times a week.
We also train and spar with the Master classes (4-1+black belts). Where theres a serious push to kickboxing in the ring.
I hope that you enjoy it and if it doesn't get you interested that it sparks the interest in finding a martial art that does. There's no wrong or right martial art - only what works for you.
I'll probably even look into Tae Chi Chen at some point probably via TKD after starting out in kickboxing. Who knows
One last point I forgot.. get that hot bath ready to sooth those tired aching muscles during those first few weeks!
