I have a few more ?'s about the trains. Do you the have room for luggae and if so how much? 2nd, do I need to buy my tickets in advance or can I buy them when I get there? I am not sure if I am going to do a trip to Paris from Brussels or not but it might be a last minute thing?

Room for luggage? Yes. More than you can lug, so don't worry.

Advance purch required? No. There may be advance purchase discounts that you could take advantage of, but not always. You can buy tickets when you get there - which is what those who live there do anyway.

Thalys often gives pretty deep advance discounts. I would check the price situation on the day or days that you are considering the trip. If there is a "good" discount consider firming up your plans.

Watch the Thalys.com site for bargains. For example: right now, you can travel First Class from Paris to Brussels for 55€ (same fare for Second) instead of 128€.

There's room for luggage, but you need to be able to handle it yourself, no one to help you.

So not more than you can get up the stairs onto the train car. The store in the luggage rack at ends of cars, or in the overhead racks (smaller than airplanes) above your seat. Sometimes room for them on the floor depending the seat configuration and how crowded the train is.