To make new friends, you can either look for them on the "Members" section of Townhouse (see screenshot below, the last option in the drop down menu), or simply find them by exploring groups and forums and looking up who is taking part in the conversations.
When other writers send you a connection request, you will
see their request notified to you in the top right corner of your screen, next
to the option "Friends". In the screenshot below, I can see I've got
five Friend requests.
If I click on the option Friends, I then have the option to Accept or Ignore the request.
On the "Friends" page, you will also be able to see the list of your friends.
Select one of your friends and decide whether you want to "Follow" them (loudspeaker icon) or "Message" them (envelope icon).