So I don't know if any phone that a USB stick will fit into without and an adapter. S9 does come with a USB c to USB a so you can plug it in to copy files to and from your phone. You can also plug your phone into your computer and copy files to it that way also.
Now if you are talking about your charging cables being all micro USB they yes Amazon sells all kinds of the converter from micro to c. https://www.amazon.com/dp/B07DMHHBJ7/ref=cm_sw_r_other_apa_i_vXnbDb2JGG5XE
I use these USB-C adapters on my older Micro-USB cable which I interestingly found to be flush with the device. Not exactly the purpose of the adapters but I'll take it. https://www.amazon.com/gp/product/B07DMHHBJ7/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
P.S. Everything is USB-C now for the most part, but I got the adapters because my wireless charger still takes Micro-USB and I didn't want a second cable on the desk.