iPhone is an apple product. Androids or smart phones are the main competitor. In the US, market share is about 50/50, but worldwide, Android dominates.
With Apple, you only have access to their apps and it's not very customizable. With Android, you have access to apps from many companies and it's very customizable.
Both are easy to use. You can find cheaper Androids but iPhones are always expensive. Neither lasts much beyond 4 years. Both stop providing updates after just a few years.
My current Android (Pixel 2) is about 6 years old, so I'm no longer getting system updates, but I have a good antivirus and other security, so I'm not worried about safety. It cost me over $600 and new ones are about a grand. I like to have a phone with a good camera, and I prefer pure Android to the customized ones from Samsung, etc. I also want a fast processor. My fiancee has a cheap Samsung Tracphone and it's slow, has a crappy camera and the wifi speeds are a fraction of what I get, but she only paid about $100 for the phone and one year of service (no monthly bill).
How much memory you need depends on how you use your phone. I have thousands of songs on my phone so my 64GB phone is close to being full. Next time I want to get 128GB. But if you're not planning on using your phone as a music player, then a lot less memory will be fine, as long as you don't install too many apps.