Have used trains and busses to travel, but which works best from Bruges to London? We have used the Oui Bus to get to Bruges from Paris. Cost is a factor but not a deal breaker.
You need to get two trains, first to Brussels Midi, then a Eurostar train to London.
Trains from Brugge to Brussels are every 30 minutes, Brussels to London every 1-2 hours.
You can buy tickets on the Eurostar website, here: https://www.eurostar.com/ You need to select the starting location "Any Belgian station (via Brussels)", which will give you a ticket valid from Brugge.
Doesn't your other post say you arriving in the next 24 hours in Brugge?
If you are leaving very soon for England you have left it far far too late to get any kind of a decent fare on Eurostar. Believe me as you are using buses from Paris you won't want to pay the last minute fares on the train.
You will be left with going on the bus from Belgium on the Eurotunnel or ferry to England. It will be much cheaper if you can get a space in August, but far slower than the train.
I don't want to encourage you to expect to be able to catch a plane from Brussels to London. There is a massive strike coming on Ryan Air and the cheap flights are being properly disturbed to pick up the slack - but in August there is very little slack to pick up.