I am trying to learn how to connect to my Raspberry pi 3 to my laptop without internet or a router. I know some have suggested that I use an Ethernet cable, but my computer (Windows 10) does not have an Ethernet port. I do have a cable with a USB connection on one end and an Ethernet connection on the other. That or I have a USB/Ethernet adapter. I am a beginner, so any help will be welcomed and appreciated. Thank you.
I directly connected my Raspberry Pi 3 to my MacBook (which has no Ethernet port) using a USB Ethernet adapter, plus a short ethernet cable and an ethernet crossover adapter. I could then ssh directly from the Mac to raspberrypi.local . No internet, router, or video monitor needed.
If you do this, make sure ahead of time to enabled ssh on your Raspberry Pi's SD card (boot/OS).
I then used the wired ethernet connection to configure my Raspberry Pi's WiFi adapter as an access point (with an IP address and DNS services), and could reconnected from my Mac to the Pi over WiFi (again, no router needed).
Yet another option is to get a USB debug/console cable such as: https://www.adafruit.com/product/954
Yet another option is to use a serial port interface board/hat on the Pi and a USB to serial adapter with your laptop.
If you use an Ethernet patch or straight through cable you can directly connect the Ethernet port of 2 computers together. This is different from the common Ethernet cable which crosses the 4 pairs of wires. This is termed a cross over cable and is used to connect computers to switches and routers.
Patch cables are also used with patch panels and connecting switches and routers together if they do not have a smart port.