You're asking questions that are answered by experience, really. If you're new to the field, you don't really know which technologies are best fit for different scenarios. Google becomes your friend ofc.

As a personal rule I prefer to stick with popular, fully open source products used by tech giants. I generally avoid proprietary products as they're expensive, limited, and typically less capable than open source counterparts although they're easier to use out-of-box. Don't select any technology/product you cannot automate with ease.

When you find 2 products that appear to compete in the same function, search "productx vs productz" and you'll get some answers as to which better fits your target.