The answer depends on which 'screening' test you are taking.
There is a test called the TOSS Test which is similar to the MASS and POSS tests which you can find information about on this site with a simple search. That test is the kind that tests your abilities more than your knowledge. It is about spatial abilities, logic, math, reading comprehension and other such subjects.
There is another test called the NUF (Nuclear Utilities Fundamentals) which used to be called the NEU or Northeast Utilities test which covers RP Fundamentals like half-life calculations, decay modes, gamma and neutron interactions, air activity calcs, and related subjects. It is more RP specific and may require some significant dusting off of disused brain cells if you have not been using them recently. If you never had to deal with that information in your previous job, you need some serious study. Information for that test can be found on this site including study guides and some practice test questions.
There is another much more serious test called the NRRPT Exam which is a real bear and requires more experience than you seem to have even to sit for the test. Although some utilities require that their techs pass the test within a certain time span of being hired, no one really uses it as a 'screening' test... only the NRRPT and approved proctors can give the exam.
The test you are probably going to take is the TOSS or MASS test. Do a search on those words (or POSS, which is for Operators) and you should find what you need.
And, welcome to Nukeworker.com
