When you start HoloIRC, you should see "Snoonet" on the left (https://i.imgur.com/F2USLGC.png). You can click this to connect, then type /join #infertility. If you don't, hit the plus arrow at the top to create a connection (and if you do, but you wish to edit the connection anyway, simply hold your finger on "Snoonet", then click "edit"). This is what the connection should look like: https://i.imgur.com/27lCJws.png (click auto-join channels, and add #infertility if you want your client to automatically connect to the channel), once connected just type /join #infertility to connect.