Rebuild Child theme and install BuddyBoss Web Pro on WP site

We have a WP site running on a Boss theme with a very basic child theme. Since the Boss theme is no longer supported, our Directory no longer works - critical error. I bought BuddyBoss Web Pro to update our theme but it doesn't run with our child theme and crashes the site. I need to have the child theme rebuilt and the BB Web Pro installed. I'm assuming this will fix the Directory. Other problems of lower priority but still important - 1) a custom plugin attached to Pinpoint Booking that allows residents to cancel tennis reservations, no longer works, 2) sometimes we bump up against our CPU max and the site goes down for a few minutes before coming back up. I'm not sure how much the CPU problem has to do with the theme, but I've also been told our site is a bit "convoluted". The most important things that have to be restored or maintained include: 1) Directory, 2) Reservations for transient slip, clubhouse, and tennis court, 3) Payment system (credit cards), 4) Upcoming Events, which is in the top right-hand corner of our landing page. 7) Reliability of website, 6) Restoring custom plugin for tennis cancellations would be a plus but not absolutely necessary. Right now, everything works except the Directory and the custom plugin. We are hosted by GoDaddy. It's free, but I have not set up a staging site. I can give you admin access to our website and access to our C-panel, if needed.