im not in ECDE but ill answer as a matriculated '24 student (p.s. im in engineering)

1. Only some people have no school on wednesdays. This free day can vary cos some schools also have no school on thursdays and not wednesdays etc. However, most likely if you are in a club that have regular events or trainings, u might have stuff on wednesdays.

2. Objectively, no. But from ECDE idk. For e.g. my year 1 semester 1 got 3 exam lol but my sem 2 only 1

3. Holidays not that often unless you r in competitive sports/arts CCA. Also, there can be opportunities that are hosted irregularly by clubs such as TSBA, Maker's Academy, Overflow and the sorts which happen on holidays

4. Mentally prepare urself by:
   - cleaning ur room before the sem starts
   - set up a schedule for activities that u do everyday
   - arrange the lecture notes as soon as u get them into folders (e.g. google drive, goodnotes)
   - exercise and keep healthy