Taking pictures of stars is not that easy, but it helpes to follow some basic guidelines:
MF! Focus has to be near ∞ -or be ∞ (NO AUTOFOCUS)
High Iso (untill too much noise)
Down with the f-stop value
And the shutter has to be longer than one second, but keep in minde that the stars will get a tail if the shutter is too long, to prevent that use the “rule of 600” it’s just that you divide 600 with the focal length you are using. That gives us roughly how long shutter we can use before the stars starts tracking. (example: 600/35=17 sec)
Try it for your self!