WordPress site tips

Hey everyone,
I'm running a cleaning service in Germany and recently built our website using WordPress with the Astra theme and Spectra. I've optimized the images, but the site is still loading very slowly. I'm hosting with SiteGround, but I can't seem to figure out what else I can do to improve the speed. Or is it impossible to achieve a high score in google page speed. If anyone has any tips or advice, I’d really appreciate the help! The website is: https://brvg24.de

Thanks in advance!