There is plenty of explanations at Version Control with Subversion but here is the short version: on the server run
svnadmin create /path/to/repo
to create the repository directory and setting up the needed files in that directory. On the client set up a temp directory with the three subdirectories
branches/
tags/
trunk/
and put the stuff you need in trunk/. Then in the temp directory execute
svn import . svn+ssh://server/path/to/repo --message 'Initial import'
So when you want to use it, checkout with
svn co svn+ssh://server/path/to/repo/trunk repo
and you’re on your merry way!