Canton fair is split into 3 stages, each lasting 5 days each.
There are 17 halls for each stage, so you’ll not have time to visit every hall.
Select the categories you are interested in and just focus on those halls.
If you’re looking to import container loads, then this is probably the best fair to attend, as the amount of categories and products is by far the biggest selection than any individual fair there is.
If you have a specific category, then there are specialised fairs in China, Hong Kong and globally, but as most factories for consumer products are located in China, that’s where I would suggest to start, as long as your order quantities are viable.
If your orders are small, say a retailer, then start with the Spring or Autumn fairs at the NEC.