got my new imac 24 it only has 2 thunderbolt ports need more usb ports and is there adapters for thunderbolt to usb

Welcome to the Apple Support Communities.

This is a simple adapter for what you need: USB-C to USB Adapter - Apple.

You could also look at a dock for more ports, such as the CalDigit TS3 Plus Dock - Apple or the CalDigit Thunderbolt 3 Mini Dock - Apple.

Jack

If you want more TB ports you will need a dock like the Kensington SD5700T Thunderbolt 4 Docking Station. It adds an additional 3 TB ports plus other connections.

USB C plugs into the Thunderbolt ports. I also have a new iMac, although with two Thunderbolt and two USB ports. My two USB drives are plugged into the Thunderbolt ports at the mement, and run fine.

I got the owc Thunderbolt 3 dock, and it works just fine:

https://eshop.macsales.com/shop/docks/owc-thunderbolt-3-dock

There are many. Easiest: search Amazon.

apart from what the rest says then you realise that the thunderbolt ports are at the same time usb-4 ports using the usb-c connector which both thunderbolt and usb-3 and usb-4 uses and one can get converters from usb-c to usb-a (the port you likely view as an usb port)