Don’t ever skip a class unless you absolutely need to. If you feel well enough to get out of bed, then do it! Soreness, fatigue, anxiety about anything (from the first day to presentations), or anything else that isn’t a legit reason to miss a class shouldn’t be done. Once you miss that first one, it makes it easier to skip repeatedly. The last thing you need is to get a bad grade simply because you chose not to attend class. Make the most of your college years! Sleep is important, but there’s more to life, and college, than sleeping in or being excessively lazy.