Update, fix bugs and optimize speed of Elementor / Wordpress website

I have a small website for my business that was built using Elementor / Wordpress. There are some issues with the website that need to be fixed:
- some parts of the website (like header layout) get broken when updating Wordpress, Elementor or when trying to move from Astra Pro to Astra theme
- form submissions appear in the Elementor->Sumibssions tab, however, I don't get email notifications
- issues with bots filling out forms and most likely sending out emails from my account
- website loading faster on desktop than on mobile and faster through https than http

Other details:
- please note that the website is in Polish, however, you can switch the Dashboard language to English
- I will send you the link to the website in a direct message

Thanks!