how i can control this padding/margin here in attached pic?

Hi there,

theres a few ways, do you want to reduce the space ?
If so, edit the Block Element with your title and post meta, select each of the post meta headline blocks, and set their bottom margin to 0 as they are <p> tags they automatically attract the customizer body margin-bottom

Hi David,
Thanks for your reply.
And yes, I'd like to reduce the space for this case.
I've fixed the space from the hook side according to your guide.
But still, there is space in "div.entry-content", how I can control this space and adjust it easily?
Attached with a pic.

Regards,
Jesse

Its defined by the Content Separator in the Customizer, but thats a global setting.
What you can do is use this CSS:

.gb-container + .entry-content {
    margin-top: 0;
}

That will remove the margin when there is the Container block hooked in before it.