Please explain to me the diagram in the attached file
How to determine which channel is noisy and which channel is the best
Example: Channel 6 with interference: -34, Noise: 90

So... I think that the interference level shows the periodic bursts of WiFi energy on a given channel, whereas noise shows the average noise floor over time from both wifi and non-wifi sources.

Based on your photo, I'm thinking that channel 3,4 or 12,13 (if available in your region) would be the best channels to try to operate this AP on. Things are looking pretty noisy though across the board! I'd also make sure that you're using just a 20MHz channel width, and not 40MHz.

Most 2.4GHz WiFi AP's and routers by factory default or by automatic setting use 1, 6, 11... so you can sometimes see better performance by setting up your AP in the valleys between 1, 6, and 11.

RSSI Means Receive Signal Strength Indicator: This is a value used to determine how best a radio link would perform with minimal or no interference on the link, RSSI value such as -30 dBm, -60 dBm is a good value.

Noise Floor of about -100 dBm and below is a good value, another good value is -106 dBm, Noise floor of about -89 dBm means the radio link will not perform at optimal service such link will have lots of interference.

Between -70 dBm and -80 dBm is a good value frequency less prone to possible interference according to the spectrum analysis

I'd also be interested to know from Cambium exactly what this shows. I had always assumed that the blue was Wi-Fi interference and the red was non-wifi interference. But Eric suggestion of a total amount of interference over time is also plausible.

Regarding what channel to select I would suggest trying to avoid adjacent channel interference. From the table below your image you should be able to confirm but I believe you have APs on channel 1,6 and 9 in the surrounding area (with channel 9 perhaps on a 40Mhz wide channel)?

If that is true I would suggest selecting channel 1. Although other channels have less interference they also suffer from adjacent channel interference. Meaning that the AP will hear interference on some of it's own channel. The problem with this is because only some of the signal is being herd it can't understand the interfering signal.

In comparison with channel 1 which will receive co-channel interference, your AP and your neighbors AP will be able to understand each other. This means they will have the ability to know when each other will be transmitting and for how long. With this information they can try intelligently and avoid each other.