Hi @Anita69,
Please see this post for an explanation of how this process has changed in more recent versions: Delete article button has disapear
To entirely delete submissions from OJS does require use of the command line utility, however, which I realize does require some more advanced skills. However, not allowing for the easy deletion of submissions is in place in order that OJS can retain a record of all submissions and to prevent submissions from being erroneously deleted.
-Roger
PKP Team