If I am on Spanish 2, will Spanish 1 words come up for review as part of my classic review? Or do I need to go to my course list and check all the time if there are words to review?
If these are two separate courses, they will not come up for classic review at the same time.
However, on the web version of memrise, you have the option to select one of the topics you are doing - in your case, Spanish - and then you can select review. You will then review words from across any courses you are doing in that language. At least, that is how it has worked for me in the past when I have tried it.
When you say you are on “Spanish 2”, which course do you mean? I found your profile and you don’t appear to be doing any official memrise courses.