It's all part of the experience that is Kenya! Don't panic!
Most of your comfort break stops will be based around curio shops where in order to use the facilities or buy drinks you are tempted into shops to browse and haggle (now either you like this type of thing or you don't) it is unlikely that you will ever stop anywhere whilst travelling on the road where you are not subjected to the Kenyan sales techniques!!
I named it the "tourist trap" because that is exactly what it is (don't worry you are not held against your will, forced to part with money or threatened in any way - remember that Kenyans are truly wonderful people they just want to earn some money). When the vans pull up you are faced with a row of traders selling their wares and it is quite a challenge to get past them without someone latching onto you. I tried the "I'll come back later technique" and then tried to walk the long way round back to the bus avoiding the sales area but I was spotted and headed off at the pass, so I had to give a very firm but polite no thanks and she went away.
The term "tourist trap" could be equally applied to any of the tourist places here in the UK - Blackpool, Brighton, London etc. It's just a place where all those visting go and it has all the trappings - the gift shops and the people with small animals offering you a photo opportunity for a small price etc. Relax - you will be fine.
Enjoy Kenya for what it is - a truly wonderful country with lovely, friendly, helpful people. More than I can say for London!!!