First thing is to check CDG website to find location of EasyJet counter. also, make sure you know their policy regarding pre-printed boarding cards. Some LCCs in EU require you to pay extra if you have to print at airport or even talk to a counter agent. Also check your luggage fees and size limits for everything--even overhead bags.
No advice can be given for immigration/customs except if you carry only, you'll be better served w/time. Those aspects vary with date, day, traffic, etc.