Moving/Copying single files can be done by using TortoiseSVN → Rename.... But if you want to move/copy a lot of files, this way is just too slow and too much work.

The recommended way is by right dragging the files to the new location. Simply right click on the files you want to move/copy without releasing the mouse button. Then drag the files to the new location and release the mouse button. A context menu will appear where you can either choose Context Menu → SVN Copy versioned files here. or Context Menu → SVN Move versioned files here.