To adjust something means to change it to fit conditions. For example, you can adjust the temperature on a thermostat if you get too cold or hot. In that situation, you can also use "set" because you're configuring the thermostat. Set can be used when you're configuring something like an alarm, timer, thermostat, etc. to do something with a certain amount, at a certain time, at a certain temperature, etc.

to set is to make as a display of what you have decided what it should be eg time ,arrangments etc to adjust is to make changes to what that has being set so as to make it better / to alter eg i have to adjust the table arrangements that you have set / you have set the tables , but i dont like how its set so i shall make an adjustment We have set the meeting for 9 am 2morro , and we will not adjust it just because someone cant make it on time

"Set" means you know what the specific number should be. "Adjust" means you are exploring and changing the setting to find the right number. "Let's start by setting the thermostat to 68*F and see how the living room feels. If it feels too hot or too cold, we'll adjust it."