technical changes for a website

The website is a platform for Italian students (12-18 years old) to help them in choosing their future school. I need some technical changes due to some issue that I cannot solve briefly on my own. ScegliScuola site ([login to view URL]): platform: wordpress management: elementor (pro) Problem list: Site speed: Optimize performance to increase upload speed on all devices Homepage search: Under the "school address" item of the search bar, there are duplicate entries that cause searches that do not exist even when the schools are present in the site database and are therefore to be grouped. Student registration form: Following registration, the redirect must be on the last page visited and not mandatory on the homepage. Review form: when the user is not logged in, in the writing that appears at the bottom of any school page, the word "connected" contains a redirect to a non-existent page, while it should be towards the login page, therefore it is necessary to change the link. When the user is logged in and enters a review, their submission is very slow. Login: When logging in with an account already created the redirect is on a page other than the last visited that I can't identify within the site. The redirect should be on the last page visited. Material insertion on the pages of schools: When I insert the texts from the appropriate Page of Wordpress (institutes), I have no way to insert the photos and if I insert them on the single page from wordpress me it loads them on the whole site, not only on that school. School’s page: In the images section, photos and videos should scroll as carousel, not columns, or anything else. They must also be the same size (thumbnail) with zoom ing. In the text spaces below, the writings must be interrupted after a few lines (especially on smartphones); to view them entirely there must be a kind of curtain that shows the text in full. Technical specifications of individual changes: Back-up and verification of both theme and CMS files Site speed: Verification of the actual use of the various plugins and possible removal Image optimization Verify server performance Installing Cache Management Plugins Seo optimization Home page search: Delete duplicate TAGS within the database and code Student registration and Login form: Removing the duplicate theme Creating a child theme and customizing the redirect function Review form: Correcting code that alters the basic functionality of CMS Material entry on school pages: Creating demo content as a correct configuration reference Training for the correct setting of pages Inserting images: I think that the chosen theme can’t allow the upload of the images in the single page of a school. I have two ideas about that, 1. Create a plugin for the theme to make it possible, 2. switch the entire site to another theme. I accept new proposals about that because I’m not really into it.