Charlie, for the most part, what hooks many choose is a personal matter. Some patterns do look better or hook up better with specific styles of hooks, but brands again becomes a personal choice. You will likely get many opinions about specific brands & styles for specific patterns. Unfortunately, a lot of what we all choose is based on trial & error.
Since you're just getting into tying, I'm guessing that you're copying known patterns, so in that case use a hook that fits the pattern. For example, if you're tying scuds, there are several scud hooks on the market made by various manufacturers. If you're tying Catskill style dry flies, use an appropriate dry fly hook. Most pattern recipes will specify the hook that the person who is supplying the pattern prefers or a basic style. In the case of basic styles, you then have to choose for yourself the brand.
It may simply boil down to price, or you may eventually find you like a certain brand over others, which means you may pay a higher price. That preference will come in time as you try different brands & styles.
Another example, if you're tying Woolly Buggers, you may want a 2X or 3X long streamer hook, or perhaps both in sizes you use most. Or you could simply use a standard shank wet fly/nymph or streamer hook. There's no rule that says you have to use a specific hook for many such patterns.
In many cases, there will be styles of hooks made by several manufacturers that mimic the models by other makers. In that case you can often cross reference them to find equivalent hooks from the different makers. There are some charts on the internet for this.
As far as a single source, that's up to you to determine, should you wish to get all your hooks from a single source. (Either a single brand or single vendor.)
I don't tie a lot of trout flies, but do have a large stock of hooks I've collected over many years. It includes many brands & styles (& prices.) You may want to check out Allen Fly Fishing & compare their hooks to what you've been using. IMO, they have a very good product based on those I've obtained from them, plus very good prices, especially when they have sales. Sign up for their newsletter too!
Recommendations for what styles & sizes to stock is also a personal choice issue. We all have different needs for what we tie. Go with what you tie & use the most of and add as you need. I believe most of us do it that way.
I tie primarily bass & saltwater flies & use a lot of big sizes & styles that are not always sold as fly hooks. It's easy to get overwhelmed unless you know what you need.
Here's a small sampling of some of my current stock.
As you can see, there's a lot of variety in both brands & styles!