As a rule, for Instagram and other social media platforms, mobile proxies are the most reliable option. However, residential proxies can also work if you have a high-quality provider.
Regarding the “how to use” part -- you’ll need to explain more clearly what exactly you’re trying to do, because there are many possible scenarios.
Most likely, you want to create multiple Instagram accounts and perform different activities from each one? In that case, in addition to proxies, you’ll need an anti-detect browser where you can set up several profiles for different IG accounts.
So, if you’re looking for advice here, please share more context.