Belgian rail - Go pass??

[Kalanchoe]

Hi,

I'm going to Belgium for a few days next week with my partner and I'm trying to figure out which is the best way to travel around i.e which tickets are applicable for my journey and also cheapest!

We're flying into Charleroi on Tuesday and staying in Bruges for a few days, and then returning to the airport a few days later, with a short day stop off in Brussels on the way.

Which tickets should I get? We are both under 25 so the Go Pass is an option but are there any restrictions on it? Also if I got a Go Pass 1 would it only be used between say the airport and Brussels, and I would have to buy a new one for the trip between Brussels and Bruges?

I'm confused! There are a lot of options! Any help would be great, thank you.

K x