To Create a Branch in SVN go to /path-to/svn/repos

svn mkdir -m "create branch directory" file:///path-to/svn/repos/<folder>/Branches

# all one line
svn copy -m "creating release branch 1.0" file:///path-to/svn/repos/<folder>/trunk file:///path-to/svn/repos/<folder>/branches/RB-1.0

Now switch

go to checked out directory ex(/path-to/public_html/)

svn switch file:///usr/home/svn/repos/<folder>/branches/RB-1.0/trunk