Eurostar Paris to London

Can anyone advise on travelling by Eurostar from Paris to London. Have booked for next month but am a little concerned about how much time to allow for check in and of the actual procedure of checking in. Just that I have been reading some horror stories on trip advisor. And any other info that I should be aware of would be much appreciated.

Every time I’ve used Eurostar it’s been very straightforward. Last time when I dropped my son off we arrived about 20 minutes before the train left and all went smoothly.