https://www.canada.ca/en/immigration-refugees-citizenship/services/immigrate-canada/express-entry.html
The process you need to follow is called Express Entry. If you haven't heard about this before then definitely you need to read a lot more. If already have, start following the steps mentioned on website and wherever you are struck, search the answers in already posted threads. Keep reading a lot because you will have a lot of questions all the time. Some can be answered even before your stage for the question comes in.
I would say, hiring immigration agent is not needed. The process the lengthy and time consuming, but it can be done on your on. Rest, it is your choice.
Start with checking out your expected CRS score. Google CRS score calculator. Put the details it asks for and an assumed score for IELTS. Compare your score with Pool's cutoff and see whether you need to improve score or just go ahead with it.
But the process needs a lot of reading.so be ready for that. Read throughly and if you are unable to find answers then create a new thread as you did this one.
Good luck!