There will a time when SOLAR opens up again for the summer/spring session (around March I believe, I don't remember). When it does, you just add the courses that you want to take and thats it. There isn't any other application you need to complete. Yes, the term will be 2 months regardless of what course you are taking. I hope this helps!
Also, choosing a program to enter in 2nd year is completely up to you. I suggest researching a bit on some programs you would be interested in by looking at what courses are required for each and judging your own strengths and interests. Each program has its own quirks like co-op opportunities or even more specializations within the program. Remember, you get to choose 4 programs for second year and you will be able to choose from the ones you are accepted in.
I hope this helps
