Hello @SergeDutchADA, welcome to the community!
is free.
You must have this amount to have voting power in Project Catalyst, but that is not delegating (the exact amount is currently 2 950 ada).
The purpose of the pools is to participate in the consensus. It is where delegates delegate their participation. This means that even if you do not have the time or resources to run a stake pool, you can still delegate your ada to another pool operator and have it staked on your behalf.
This is an excellent compendium of articles on the subject, where you can find a lot of interesting information:
About Cardano Staking - A compilation of Contents and Resources
Greetings.