If you're 100% willing to do it right and dedicate time for doing good research about the whole process and its requirements, then I'd suggest you do it on your own. All the info is available online!
If you're the kind of person who quickly gets lost while doing research, and you simply don't wanna bother, go with consultancy. But then, you lose control over your application, and run the risk of having to deal with a mistake they could make.
WES and IELTS/CELPIP are the two first big steps, and the most time consuming ones. So I'd suggest you start both of them simultaneously.
Book IELTS, and while waiting for exam date, gather your WES documents and send them.
First you'll have to check on WES website the required documents specific to the country where you obtained your degree.
Then, if WES exclusively only accepts transcripts sent directly by the school, you'll have to check with your school directly.