How do I buy sats?

As a novice investor in the cryptocurrency world, I'm quite intrigued by the concept of 'sats' and its potential role in my portfolio. Could you please elaborate on the process of purchasing sats? I'm particularly interested in understanding the steps I should follow, from setting up a wallet to selecting a reputable exchange platform. Additionally, are there any specific factors I should consider before making my first purchase, such as market trends or transaction fees? Your guidance would be greatly appreciated.