Frontend Member Registration and Private messaging

Hi there

im stuck with my page, need some help on code mechanics…

How do i create a member registration form in the frontend?

How do i create a “send private message”-form in the frontend.

i found out how to display usernames, images and other member related content, but not how to enable to corresponding functionality

Can u help me? and if possible not by just linking to solspace 😊

Thanks in advance