When you delete a photo in Lightroom, you have 2 choices:
1. Delete from disk.
2. Remove from catalog.
If you delete from disk, it will be deleting "off of your computer".
Obviously if you have photos you don't want they can be deleted, but as far as cleaning up space without deleting photos, I have these suggestions:
* purge the acr cache.
* there is also a video cache which can be purged.
* remove all 1:1 previews.
If that doesn't free up enough space (along with emptying recycle bin, and deleting temp files, e.g. internet, then you need a new drive - external for photos would be OK).
Is there a way i can delete pics and clean up space in lightoom?
Just to clarify, the photos are not in Lightroom. All photos are stored on your hard disk.
Deleting photos from Lightroom, and choosing "Remove from Catalog" will not save you much space at all.
Deleting photos from Lightroom and choosing "Delete from Disk" will save space, but then you don't have the photos any more! If these are photos you don't really want to delete, an external Hard drive is a very good solution.