There is no fixed syllabus for UCA test . It just include the basic coding questions using C and C++(mostly from 2nd year syllabus)
I myself was not in the UCA batch but my friends were. If you truly love coding then you must join UCA batch else take things lightly don’t overthink if you don’t get selected.
You can directly go to the teacher(UCA batch tutor) and ask them to take you in the batch(if you don’t clear the exam) as you love coding, they will ask you basic questions about coding that you might have studied in the second year.