New repository can be created with two different options:
Execute following command. It will create a directory for the repository, but parent path has to be present. i.e. in the following example,
/var/svn should already be there, while it will create
svnadmin create /var/svn/my_repository
If you are using TortoiseSVN, you can use GUI to create repo.
TortoiseSVN -> Create Repository here...