Time needed at AMS airport

If you book the train in advance give yourself 3 hours to make it once you know for sure that your flight is going to arrive on time or just wait until you get there. Also I would avoid booking with Thalys since the prices are higher than on Dutch and Belgian rail. Thalys has wifi and food options on board Dutch rail does not but there is a grocery store at the airport you bring your own food which is better anything that you'd get on a train.
https://www.nsinternational.com/en

Also a ticket on Dutch rail is good for any train time that day. There is no reserved seating.
Thalys is only good for a specific train and time.

Here is info on your options
https://www.seat61.com/international-trains/trains-from-Amsterdam.htm

Just to clarify a bit on what’s written in post #1. There are no direct trains from Amsterdam Airport to Bruges, you will always need to change trains in Belgium at either Antwerp or Brussels. In order to get from Amsterdam to Antwerp/Brussels there are 2 types of trains; the highspeed train called Thalys and the normal IC (InterCity) trains. Tickets for highspeed train Thalys use airline style pricing with the cheapest tickets sold first. Thalys tickets are tied to a specific train and include a mandatory seat reservation. If you miss your Thalys train, you’re out of luck.
The regular IC trains are mass transit. There is free seating and tickets are only tied to a specific day. On that day you can take any IC train from Amsterdam Airport to Antwerp/Brussels you want.
The Antwerp/Brussels to Bruges portion will always be on a local train, again with free seating and tickets not tied to a specific train.
Tickets for IC trains from Amsterdam Airport to Bruges cost €57,80. If bought > 7 days in advance, you can get the early bird fare of only €29

So if I were you, I would buy an Early Bird ticket for Amsterdam Airport to Bruges for the non-highspeed service. Watch out! NSinternational also sells tickets for highspeed train Thalys, so if you go to their website to book your tickets, make sure you select the correct ticket. You will know you have selected the flexible and non-highspeed ticket when it gives you a fare of €29. The ticket system will make you choose a specific time, but your ticket will be valid on all non-highspeed trains from Amsterdam Airport to Bruges.

....and to add on to the previous two posts.

I can concur, just purchase an early bird ticket for the non-high-speed trains. The high speed options only save you a little time (15 to 45 minutes) and are less flexible, with this ticket, you get to the arrivals hall and hop the first train to Antwerp.

Most likely your journey will be a change in Antwerp, then another change in Ghent, to Bruges. Going through Brussels is further out of the way, even with high speed trains, the time gained is lost from Brussels to Bruges for the most part.

Either use the link above for the NS site, or at least be aware that you want to book on the NS International site and can not on the regular NS site. Always been frustrating that it is not all one site and app. If you will have a phone with service and data, download the various train apps (NS, NS Int., and the Belgian one)

Also be aware, the 29 euro early bird fare is 39 euro on Friday, Saturday, and Sunday.

Thank you so much! This is very helpful information. I love all your detail!