LE sadly does not come with TTs-1, not sure why as it is certainly more useful and better sounds than the 3 included soft synths. Most of LE works the same as ( assuming) X1 as far as menus and midi editing go, but it's not much to get excited about due to the lack of VST's. It's best attribute is as a cheap upgrade path to a new version of even Artist which will blow it away 10 fold.
Anyhow follow the help files on inserting and using the VST's.
You need to insert the Drum VST and then point a midi track output at it. LE does not work like the new versions and I don't think it uses instrument tracks which is what your describing. At least the X1 version doesn't, There might be a newer version I'm not sure.
Insert a new MIDI track and put your loops in there see if that works.