The pinky finger is always the weakest when you start and it might need some practice to gain a bit more control over it.
Even simple chromatic exercises like going 1234 4321 starting from every string and every fret could be a good start. Then playing scales up and down just to get used to the fretboard.
But the best thing to do is to take a couple of lessons where teacher could work on your hand position and give you some exercises to correct bad habits early on. As your muscles grow in strenght you will be able to relax your hand a bit more and gain some more independence with each of the fingers.
Also it seems from the picture that the action on your guitar is quite high. This can be very discouraging for beginners so might be good idea to get the guitar setup correctly.