LOAD DISTRIBUTION IN ONE WAY SLAB IN SAP2000

Sap 2000 distributes one way slab load to red colored axis direction only and not towards longer edges. So you'll have to rotate your local axis of slab such that red axis points to your longer edge.

Unit weight of cement, sand, aggregate and other materials?

Unit weight of different materials like cement, sand, aggregates for engineering calculations have been provided in IS:875 (Part I)-1987. You can easily download it following google search for pdf document. IS875 Part I to Part 4 provide loads to be used for building design purpose.
IS: 875 (Part I)-1987 : Dead Loads- Unit weights of building materials and stored materials
IS: 875 (Part 2)-1987 : Imposed Loads (Live loads)
IS: 875 (Part 3)-1987 : Wind Loads
IS: 875 (Part 4)-1987 : Snow Loads
Follow this download link for legal download of all Indian (IS codes) codes.
https://law.resource.org/pub/in/bis/S03/

To prepare SAP2000 model to import in SAFE

See page 12 of https://wiki.csiamerica.com/download/attachments/8750886/Section%20Designer%20RC%20column%20and%20beam%20design.pdf?version=1&modificationDate=1331927322690&api=v2