How to do vertex form step by step?

Sure, here's a simulated question based on the paragraph "How to do vertex form step by step?" "Hey there, I'm a bit confused about converting quadratic equations into vertex form. Can you guide me through the process step-by-step? I'd really appreciate it if you could break it down into simple, easy-to-follow instructions. Also, can you explain what vertex form is and why it's useful? Thanks in advance for your help!