Theme trouble after 8 years since update

Hello WordPressors, I must admit I’m in way over my head lol. I was trying to update our 8yr old website since our rates have changed. I was advised to update WordPress / plugins by the old web developer. well, that went fine but I was also prompted with the update theme indicator. After the update, the website broke with critical errors. I spoke to some tech people and they couldn’t find a solution since we did not have backup files. Moving forward with a new theme I felt like enough things survived the update to try to make the site work. Enough background info here is my question. There is a circle on the front page that is spinning. I think used to be a picture slide show and I have no idea how to remove it. I was able to add a new slideshow with a new up to date plugin and it’s just below the spining circle. I tried to build a new page and make it the new home page but it still injects that swirling circle. If anyone could point me in the right direction it was be appreciated! thanks

The page I need help with: [log in to see the link]