The best depends on what you can afford to spend and what you want from your phone. There's a range of options available in size and specs, from the basic Apple iPhone SE up to the latest iPhone 12.
Is it better to buy an iPhone from Apple or your carrier?
If you buy your iPhone from Apple directly your phone will be unlocked and will be compatible with most carriers, if you purchase your phone via a carrier it will often be locked to that specific network.
Is iPhone 11 or 12 better?
The iPhone 12 has the latest A14 Bionic Processor which makes browsing and camera use a better experience. If affordability is important, then the iPhone 11 will have a more attractive price tag.
