It seems that many new Rise of Flight pilots are having issues with registering on the website. These server issues were supposedly resolved earlier, but there's many people still having problems.
Here's some things to try:
1. Check your email spam folder.
2. Explicitly allow all emails from email@example.com
3. Try using another email address.
4. If you're still not able to register, send an email to firstname.lastname@example.org and tell them your name, email address, and password you created, then ask them to resend. (thanks to Jason at 777 Studios)
Also, it looks like the multiplayer metaserver is down, since no servers are showing up.
Hopefully all of these issues will be resolved soon - we know that neoqb has already stayed up late working on some of these issues. Looks like a pretty rough launch :(
Meanwhile, here some general resources:
Rise of Flight Technical Support (SimHQ)
Official Rise of Flight forums
Rise of Flight FAQ
WWI Air Combat forum