set margin featured image

Hi,

I would like to set a margin for the featured images of my posts.
Currently it’s set to align center, but in this way it does not quite align with the text and with the title. I tried changing the ‘aligncenter’ into ‘margin-left: 25%’ but this did not have the desired result.

I would be very grateful if anyone could tell me if this is possible, and if so how to do it.

Warning: I’m a bit of a wordpress amateur, apologies if my question is very silly.

Thanks in advance!