Aptitude testing is implemented in the wrong way by most companys - it annoys me how it is used. The company i used to work for applied it as any other test in which the students with the best scores got through rather than looking at the bell curve (as is intended). The 4 most troubling students that I ever had got perfect scores on the PILAPT test that they used. Anyway, rant over.
You can do some prep work here:
https://www.latestpilotjobs.com/aptitudetest/ I'm not 100% sure what system they use, but COMPASS and PILAPT are the most popular for flight training organisations to my knowledge.