They don't need more sleep (reptile sleep requirements are quite different from mammalian sleep requirements, their metabolisms and so many things about their physiology are very different). It varies a lot between species. In many species young snakes are far more active and explore more than adult snakes. In others it's the opposite, but for different reasons. Mammals grow rapidly (humans are an exception) and have a very high metabolic rate as youngsters, which is why they need more sleep. This isn't relevant to reptiles, which never have metabolisms comparable to mammals (cue someone cherry picking an invalid comparison of a hibernating bear and a hot monitor lizard, haha). Mammals also have parental care, which allows babies to have the luxury of sitting around safely, not having to explore and do all the things necessary to find shelter, food, etc. Reptiles have a more risky task of making it on their own, they have to do everything required to survive without assistance (cue someone talking about crocodilian parental behaviour or something obtuse! Haha, it's silly how you need these disclaimers in online discussions!).
In general, babies often are more active in reptiles, but there are plenty of examples both ways, and they're not comparable to mammals.
There are plenty of examples of reptiles having similar 'instincts' and basically growing from small versions of the species into large versions of the species, and also examples of pretty radical changes in way of life, hunting style, etc etc. In this respect they're a pretty mixed bunch. Of course, as adults they are more influenced by the environment they grew up in, and as neonates they're being driven by instinct.
