Hello, I play both guitar and a bit of bass and i was reading in some forums that to get a beter recording sound it is important to get an audio interface. But the issue is i currently have a blackstar guitar amp that comes with an usb interface. The question is will an audio interface give me a better sound and, can i connect my amp to an audio interface?, since this recording is a hobby i was planning to geta cheap interface like BEHRINGER U-PHORIA UMC22. What do you think about it, also i have a bass but the amp is very basic one can i get a better sound with softwares like amplitbe etc?
Thanks in advance
Chances are you will be able to find amp sims that sound better than the amps you currently have, either for free or for very cheap.

Usually you don't "connect" an amp to an interface. You put a microphone in front of the amp, and then plug the microphone into the interface.

Alternatively, you plug your guitar/bass into the interface and use an amp sim like amplitube.
Quote by diabolical
Anything will give you a better sound than a Blackstar amp, well almost anything, Line6 and Crate excluded. 

The pod HD amp sims can be tweaked to sound pretty damn good with 3rd party impulses.