Assist with development/publishing of part-finished site

I am building a staging site to replace my existing website. I already have the structure and basic pages. The developer that helped me get to this stage did a very good job of building the basic site. It is a wordpress site, built with Elementor. The intention was for me to populate the site with content. Once the content was ready, the developer was going to conduct the second part of the project which was to include any snagging issues that I couldn't resolve myself, as well as checking content, building and checking links, installing SSL etc. The existing site has a good review reputation on Google and it's important to me to ensure that when the new site is swapped for the old site, I still retain the Google reviews, reputation and standings in google searches. Of course the project hasn't gone according to plan! The site has been waiting for 9 months for me to populate it with content. During that time a number of updates are pending, and I think this (together with the fact that there's currently no SSL on the staging site) is meaning that it's very difficult to get into the site. Often once I'm in, it's kicking me straight back out and then proving very difficult to log back into again. I'm loathe to instal the updates, though, as I don't want to break it further! I am now in a position to finish the content and launch the new site. Unfortunately, due to personal problems, the developer that helped me previously is not able to help me now, and I want to get this launched as soon as possible. I am l looking for a developer experienced with Elementor to help me reach completion of this project. First stage will be to get the staging site to speed up to the point that it doesn't keep kicking me out so that I can finish the content. After that, checking the site, making sure all the links work etc. There is also gravity forms on the website and a potential API connection to my studio database (I've not really investigated this yet). Then of course, swapping the finished site for my existing site, without losing my hard-won reputation.