>>2464528 I recommend discussing it thoroughly first. What are your limits and wishes? Is there something that you especially want to avoid or do? Also, set a safe word and/or gesture.
When you have decided what both of you want, search for more information. Find the safest techniques and equipment.
If you want to be spanked, thighs and ass are the safest choice.
Want a gag? Choose one that you can breath through.
Tying up? Sturdy ropes and belts that won't slide into super tight, unsolvable knots.
Pain? Hot wax, spiked mats, ice cubes, clips and, in case you want some blood, sterilized needles from a drugstore. Only one use, sterilize skin afterwards.
Big toys? Fisting? Lube.