There is simply nothing that you need to know to operate the Fender '57 Champ. It only has a volume knob to control how loud your sound will be, and nothing else at all to control your tone. While this makes using the amp a breeze, I do wish that there was at least some EQ to work with here, as beyond the volume control and the controls on your guitar or effects pedals, there isn't anything that you can do to change your sound within the amp itself. A manual surely isn't necessary to have to operate this amp.
For such a small guitar amp, the Fender '57 Champ can absolutely wail. It can get pretty loud, but since I've only used it for practicing and recording, I've never needed to have it on more than five or six. Although it can get pretty loud, I definitely wouldn't recommend using it for live shows as it isn't loud enough for that sort of use. The amp sounds incredible when using a Fender guitar like a Stratocaster or a Telecaster, as nothing beats the Fender on Fender sound in my opinion. The only downfall of the tone is that there aren't more parameters to work with here.
As far as practice amps go, the Fender '57 Champ is certainly up there with the best of them. It is built piece by piece after the classic 1950's Fender amps. However, since this is a replication Fender will charge you a whole lot of money here for a five watt amp. For this reason, I'd encourage those interested in getting an amp of any type to stray from this and get something bigger that has more versatility. However, if you're looking for a collector's item that is nonetheless a great sounding amp to be used for practicing and recording only, you can't go wrong with the '57 Champ.