having trouble with DocString settings
Which docstring settings? ST doesn't provide any special docstring settings out of the box. You can use plugins like DocBlockr or DoxyDoxygen to get some help with creating docstrings. I personally prefer the later one, even though it needs some setup to work with python docstrings.
couldn't able to execute any programs
You can run your python application by ctrl+b That key binding calls the built command which is associated with running the script of the current view.
To get some code intelligence features, you might want to try LSP package and python-language-server. Both can do code completion, linting and provide docstring tooltips quite well.
As an alternative you can try Anaconda, which attempts to do the same.
The third option was to use Python - Autocompletions which uses Jedi library to do code completion and tooltips. This would work well together with SublimeLinter.