Hi PriyaAravamuthan,
I'm Stefano an Independent Advisor, here to help you.
Windows to Go fully supports USB 2.0 (https://docs.microsoft.com/en-us/windows/deploy...)
Obviously you will see a different performace between USB 2.0 (max speed 480 Mbit/s) and USB 3.0 (max speed 5 Gbit/s). There is a 10 times gap between the two USB kind.
I would suggest you to buy an external drive with USB 3.0, if you want to be sure that your system would be fast.