Hi Alex, and welcome to Tropical Fish Keeping forum.
You have other issues needing action as well as the shark, I'm afraid, as previous posts have mentioned. Before I get to specifics, we have a fish profiles section here, second tab from the left in the blue bar across the top of the page; or, when you see a fish name shaded in posts you can click on the name and the profile of that species will pop-up. So you can verify what I'm about to say there.
Shark has been mentioned, and I agree; juveniles are very attractive, but they need much more room and other substrate fish are out of the question, plus these fellows can sometimes decide to attack any fish if they get "upset" over whatever.
Betta is not a community fish. It has a tendency to eat small fish like neons, or send out chemical signals that it would like to, which the neons can pick up on and they will be stressed. Plus the flowing Betta fins are an easy target for nipping from almost any tetra, danio, Barb, even normally peaceful rasbora. I would return the Betta.
And for a temperature reason also. They need warmth, Neon Tetra at 80F will quickly burn out. Stress again. As noted in the profile, this fish likes slightly cooler water, nothing above 77/78F max. Even worse for the White Cloud Mountain Minnow which are very cool water fish, nothing above room temp. They will definitely be stressed at warm temps. Zebra danio should also be closer to neons in temperature.
Danio and Clouds are shoaling fish, like neons; a group of at least 6 is considered adequate, more if space permits. This also is explained more in the various profiles.
The cycling issue has been covered, that needs careful monitoring. Removing some of the fish will help there, and improve the community as noted above.
It's a great temptation to buy a couple of this or that fish in the store, I know, I was like that once. But I learned--the hard way, after losing many fish experimenting. I now never buy a fish i do not know, I will go home and research it if it is a new species to me, and then go back to acquire some if they are compatible. Many things affect compatibility: temperature needs, numbers of fish in a group, behaviours, aquascaping/environment, etc. Only fish that share these needs will work together. Stress causes weakening of the immune system and leads to health problems that would otherwise not surface, so it is important to know the fish's needs and be able to provide them.
Byron.