How do you buy on Starknet?

So, let me get this straight, you're asking about purchasing assets on Starknet, the decentralized network built on the StarkWare zk-Rollup technology? If that's the case, you're in luck! Purchasing on Starknet is a fairly straightforward process, but it's important to understand the basics first. Can you tell me if you're familiar with the concept of decentralized finance (DeFi) and how it differs from traditional finance? This will help me tailor my explanation to your level of understanding.