I am new to gis modelbuilder. But as I don't know python, are there any websites where python script tools are available i.e. user made for Arcmap???
You might want to explore pre-made solutions prior to reinventing the wheel... or you might find some parts here
http://codesharing.arcgis.com/ the code sharing site
or even https://community.esri.com/groups/python-snippets?sr=search&searchId=4f41f386-9a5f-49e2-b340-79d32ec... and within https://community.esri.com/community/developers/gis-developers/python?sr=search&searchId=93fd412f-9a...
ArcPy is the python module fir most ArcMap tools. There are many resource list fir learning Python, arcpy and other geoprocessing skills (beyond model builder) already on geonet. The help documents include many good code snippets and samples on using Python/arcpy, in fact, almost all the ArcGIS tools show samples of using the command line or have sample scripts.
you may want to start What is ArcPy?—Help | ArcGIS Desktop