I want to try to help you:
First of all, I would like to recommend you a very useful online learning platform of the QTrap5500's manufacturer Sciex:
SCIEX Eduction / SCIEX University: https://sciex.com/education
This website requires your registration to benefit from the eLearning courses, but most content is free of charge. Initially you can learn or brush up the basics of mass spectrometry and liquid chromatography and then move on to specific training for the QTrap5500 instrument. Although that eLearning does not replace a real training together/by an instructor, it gives you a lot of valuable information that should allow you for a facilitated start in that field of analysis. I have followed these courses as well, which enabled a good brush up/repeat for me and I can say, it is worth spending a couple of hours following these eLearning courses. Please have a try!
I assume, that you have got synthetic (or purified) chemical standard for the micropollutant.
In this case, you may try to optimize the QTrap5500 for that compound by following the instructions there:https://sciex.com.cn/Documents/Downloads/Literature/AN_TUT_D1000076695_EN.pdf
Please look up in the literature, what solvents are suitable for this compound and make sure to use volatile ionizing agents, such as formic acid, acetic acid, ammonium formate or related... depending on the chemistry of the micropollutant. Best way is to start with infusion-MS to gain first mass spectrometric experience on your compound.
Good luck and best regards,