Firstly, welcome to the world of guinea pigs
The cage definitely doesn't look big enough. Do you have the dimensions?
The wheel needs to come out. A guinea pigs spine is not flexible, and wheels can seriously damage them. Also I can't quite make out what food they are on (in the feeder) but they should have a high quality pellet. Oxbow and Kleenmamas are a couple of the highest quality pellets available. They also need unlimited quantities of hay, and a wide variety of veggies. The hay is to help with their gut, and also keeps their teeth in shape. The veggies are primarily because guinea pigs can not make their own vitamin c, and without vitamin c they get scurvy.
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