External HDD very basic questions

Can anyone answer these two basic questions, getting a headache doing searches and not the answers I want!

I've just purchased a Toshiba 1TB external hard drive, which is great, but it connects via USB 2.0 only. (My PC is 2 years old and doen't have USB 3)

1. If I buy a new PC which will only have USB 3.0, will this device still connect to the new PC?

2. If I purchase a second external drive as backup, is there any way to copy this huge amount of data to the second external HDD via my PC?

My PC has a HDD of 1TB also

Thanks in advance for any advice here...

Rob