The $35+ Arduinos usually have a USB port. Some Arduino (non-USB) clones are now less than $20. It's still a fair bit more than $5, but when you don't know what

The $35+ Arduinos usually have a USB port. Some Arduino (non-USB) clones are now less than $20. It's still a fair bit more than $5, but when you don't know what you're doing, a kit is better than trying to acquire all the parts yourself.