What happens if i miss my train?

so ill be traveling by train for the first time and i was wondering what would happen if i missed it?
can i get on the next one?
do the trains come frequently?
are they usually late?
i willbe traveling from Paris to Brussels

Other answer:

paper:
The fast Thalys trains, which take 1 hour 22 minutes between Paris and Brussels, vary in frequency throughout the day, often there's one (or even two) per hour, sometimes there's a two-hour gap in the timetable. However, tickets are sold for a specific seat on a specific train. If you miss your train, then the ticket's no use and you have to buy a new (and very expensive) one – SO MAKE SURE YOU GET TO THE STATION IN GOOD TIME. And yes, they usually do run on time;
Christopher:
That depends on your tickets. If you have a ticket for a specific train, you must catch that train. If you miss it you will have to pay again to get a ticket for a later train.

If you have what is known as an open ticket – meaning one which is valid on any train between the two stations – you can get a later train (though if there is a seat booking you might have to wait until there is a train with spaces free.

Willeke:
If you travel on the 'normal' trains you are likely to have a ticket for all trains on that one day. But it is more likely that you have a Thalys ticket that is for one train only.
I am ze mayan:
You'd be waiting…get the next one..mm.