How to remove author and date from posts + how to resize the header media logo

Hi there,   recently I startet with my first wordpress page. I startet with the Music Journal Theme. https://www.dosenbier-band.de Like I wrote in the title, I have two questions. 1. Is it possible to remove the author and date metas from any posts on my website? I think it looks way more professional without this feature. I allready tried some plugins but none of theme worked. 2. Is it possible to resize the logo above the main menu? The file I uploaded is about +2000px wide but the theme scales it down. Thanks for your Help!