Hi Andrei and welcome to Moodle!
You can move a block using the Move icon (crosshairs), however as you've found, it's not possible to move it to the centre area of the front page.
Instead, in the front page settings, you can select Announcements to display (as shown in the screenshot below). You can also include text etc. in a topic section on the front page.
Please see 'How can I change the look of the front page?' in the Front page FAQ for more ideas of things you can do.