I need a developer to fix issue

hello guys, I have a problem with a wordpress site that i have. My host is in siteground . My webiste [login to view URL] is very slow when do actions like, creating and publishing new page, adjusting featured image, update a post, or updating/save elementor designs. The website is new and there have been created from blogger. With the mean of created i mean that it was exists on blogger for several years and since 2 weeks we decide to change it to wordpress. We choose a service of imigration from blogger to brand new wordpress. The company that make tis service transfer all the pages and posts tags in the wordpress. Also take care all the redirections that needs from blogger to wordpress through htaccess file and a plugin but the site is very slow in the above actions that i mentioned. With the mean slow i mean that it takes 30-60 sec to save or update anything. Siteground said that it is something in databases but no information more. Also to mention that the site has 26.000 posts and around 20 pages Could you help me out with the issue? Also inform me about the time and the cost and of course if you need username and passwords.