Yes, you can work full-time. The P1 exam isn't HARD, you just need to know how to organize your material. Tab it properly. Know where everything is. My friend and I created an index (took a week between both of us) that was very useful during the exam. If you know where everything is, you don't need to "study" - you just need to find things. Personally, I found the P1 exam easy (but draining); I had about 30 min left for the first part and 1 hour left for the second part. My friends found the opposite of this true (ran out of time). I think the key was really organizing my material. I brought 1 large bound LSO book, then another one where I divided it between legal topic, and then my index. I already made my own little "book" with quick information - charts, SAB, etc that I could refer too, this also helped. But find what works for you. Too much material may confuse someone else.
There is the Ontario Paralegal Association you can join. If you are a graduate, but not licensed, you can be a legal assistant and perhaps they may hire you as a law clerk (working under the supervision of a lawyer). In my experience, they all want experience, so I've been working as an assistant. It seems most jobs start that way.