Group assignment for registration 1.7.6.4

[WC Fresher]

Hi,
is the following possible with PrestaShop 1.7.6.4?
When registering, I want every customer to assign themselves to a group or
if it does not specify anything, it is automatically assigned to a predefined group.
I would be glad if someone could tell me the solution to this problem.
Many thanks for the help
Dariusz