What's the best to clean or speed up my old Intel MacBook Air 2020?

So my Intel MacBook Air 2020 (i5, 8GB, 256GB) is really slow on Sonoma, I've already got the MBP 14" M3 Pro (18GB 512GB) but I want to get some use out of the old Air as it's quite light and handy. I've come across "CleanMyMac" software, but I'm afraid to install it because it looks a bit sketchy to me. Are there any good ways (or legitimate software) to speed up my old MacBook Air? I already use Turbo Boost Switcher Pro and have Turbo Boost disabled so the MBAir is quiet 90% of the time, but in my opinion Mac OS Sonoma was a huge performance hit for this grandpa.