Welcome to Reef2Reef and to saltwater tanks!
There's nothing wrong with the Hello Reef kit per se, but I don't think it's worth it, honestly. There's nothing special in it, all they did was pick typical off the shelf items that you can get anywhere if you decide to use them (AI Blade light, Eheim heater, AquaForrest salt, CaribbSea rock and sand, etc.). Most of these things you can get at your local PetCo or other places if you decide they are really what you want. There's nothing "Hello Reef" specific in the kit.
I had originally thought that the Hello Reef kit came with the Innovative Maine Nuvo Fusion AIO aquarium, but looking at the picture now I am not so sure?
I also understand that when you're just getting started that the information they include is a big selling point. I would very much suggest you can get the same info right here on R2R for free :) There's even some
BRS TV Video series that would help you get going, also free.
Additionally, if you give us a chance, most here would do our best to talk you out of starting your first tank using that particular combination of bagged sand and dry rocks offered in the Hello Reef kit. You would be much, much better served to go with live rock and sand from a quality Local Fish Store (LFS) or online vendor.
To address your original question, you don't *need* either a protein skimmer or a UV. Both are just tools that help to maintain water. There is almost always another way to do it, and as mentioned, with a 15 gallon tank regular water changes will go a long way towards keeping a 15 gallon healthy, particularly if you're starting out with some easy to keep soft corals and others. As mentioned, you can always add a skimmer and/or UV anytime in the future if you feel that you need one, so you don't have to buy them upfront.
I've had several of the smaller Innovative Marine All-In-One tanks, these make great first tanks. I'd get just the basic IM tank kit, not the Hello Reef kit. Get the largest tank that fits your space and budget; they have 10 gallon, 15 gallon, 20 gallon Long, and 25 gallon Lagoon AIO's and anyone of them would be a great first tank.
This hobby takes q fair amount of research and learning, so from there you could learn about the different processes that happen in these tanks, and how each piece of equipment works to supportnig an idea environment for your livestock. Then, you'll be in a great place to choose your own gear.
If you have any questions, just post here on R2R and I guarantee that someone will help you out :)
Good luck with whatever you decided!
Additional resources:
See the R2R Supreme Guide linked above as well as this video series from
BRS:
https://www.bulkreefsupply.com/cont...brs-tv/beginners-guide-to-saltwater-aquariums
