Port

Hi louisefromwestminster,

Welcome to the Apple Community, where some of us do our best to help each other :)

Sounds like you need a thunderbolt to USB adapter of one kind or another.

Such an adapter is like a very short cable with the appropriate fitting at each end.

You may need to ensure you have the correct thunderbolt connection / adapter between your Mac and the item with USB outlet. ie: You may need to check precisely which thunderbolt port your Mac has.

Apple has support articles that can provide some info:

About the Thunderbolt ports on Mac

https://support.apple.com/en-au/guide/mac-help/mh35952/11.0/mac/11.0

and

Adaptors for the Thunderbolt 3 or USB-C port on your Mac or iPad Pro

https://support.apple.com/en-au/HT207443

Can be just a simple adapter, ie: very short cable between Mac and what you want to plug in

or

can be a hub, or dock that allows for up to three or four USB and / or other devices to plug in at the same time. (Eg printer / ethernet / HDMI / card slot / external hard-drive / second display.)

Sometimes simple adapters can be found in supermarkets etc, or better ones at electronics departments or stores.

The staff in electronics stores are usually very knowledgable and helpful.

And

Apple have a few adapters available online ... as "accessories"

https://www.apple.com/shop/mac/accessories/power-cables?page=1&f=adapter&fh=4595%2B45b0

Hope this helps :)