Hi Mikko and a warm welcome to you.

I would suggest that you move forward in the lessons and, at the same time, keep coming back to practicing the C chord. You will get it eventually.

Keep attention on your posture and your hand position. Keep the thumb behind the neck not over the top. Make sure your finger nails are really short and use the tips of the fingers to press down on the strings.

You are doing really well, so don't get discouraged.

Joe.