Check out a working copy (i.e. clone):
svn checkout <url> [path]
Pull latest changes from remote:
svn update
Undo local changes to file:
svn revert <file path>
Undo all local changes:
svn revert --recursive .
Note: For merging and conflict resolution use a GUI (e.g. SmartSVN), and for everything else use git-svn