You read the instructions. You kept all the cables together. But it's still not working.
Keep cables together
Unfortunately, hard-wire cables are often product-specific, so you need to keep your cables separate for each device you're setting up.
Don't "read ahead"
Step-by-step instructions can sometimes seem obvious, but for complex electronics you need to follow the steps, no matter how mundane. Otherwise, you may need to start over.
Make sure your wi-fi is working
Connectivity issues are at the root of most A/V setup problems. Make sure your wi-fi equipment is working, firmware is up to date and your connection to the internet is solid.
YouTube is your friend
Almost every product has a YouTube unboxing and/or setup video. These user-created videos can help walk you through setup carefully and patiently. They can also offer troubleshooting advice specific to the product you're trying to set up.