You’ll be assigned to a mother’s group by your hospital/child and family health nurse! The group will be made up of other girls in your area. From memory I joined mine when my baby was about 4 weeks old but she was by far the youngest in the group, so you’ve got a few weeks to bond with your baby and get comfy at home before all of that starts up.
Do you have any local pages on Facebook you could ask on? May be able to google “playgroups near me”