You can technically change those settings manually in the terminal, so either try and find a guide on that (because I dont have knowledge on how as I've never seen a need to) however on Twister OS there are theme options which allow pointer size to be changed, I suggest switching your OS to Twister if you want more pre-installed tools and asthetics as most the work is done for you and it's built off of Raspbian so there wont be much adjustment time.