I would applaud you when you do the trip around the period of Paris Roubaix. You can be lucky with nice weather, you could be in for a very tough trip when it's cold and wet. Flandres is not 'cosy'. It's flat in the West and the hills in the East are killers! They don't call a hill a hill, they call it a 'wall'... Or sometimes they only give it a simple name without the part 'hill' or 'wall'... Makes you wonder why...
If you want to test yourself climbing short, steep hills... well, I think Devon near the south coast /Plymouth has so interesting hills you can use for practice.
Flandres is used to cyclists, that's a big advantage. You could say that every car driver is a cyclist as well. That helps when it comes to road safety. But makes sure that you're visible! Some high vis clothing items and a flashing red LED light under the saddle is (imho) a must. Needless to say, wear a helmet.
I'm not too familiar with hotels in Flandres etc, but this one is a good hotel where there's enough space to store the bikes, trailer etc. Close to the motorway to Calais, in a area with very smart houses. Bruges is 4 k ms away. Big bonus about Brugge / Bruges: fantastic underground parkings and not expensive! https://www.weinebrugge.be/en/ Stay away from Antwerp. Driving there is murderous; They're busy with new roads and fly-overs, causing a lot of traffic jams. Everything west of Antwerp = okay. Traffic jams etc are nearly unknown there. Ghent is also beautiful, but not too big. Make sure you see the Lamb of God painting in the cellar of the church. Public transport in Ghent is FoC (at least it used to be - check it). The idea is to ban cars from the historic city center. Since Oudernaarde is part of the trip; check this: https://www.oudenaarde.be/en/tourism
Food and drinks: you cannot go wrong in Flandres. Stay away from the beer when you're riding. Some stuff is very, very heavy...