Hi Ceres and welcome to TFF!
You've done a great job with your description of your situation! And you've not gone overboard with your new tank, so that is all good. Good attention, wanting to get some good live food.
Bloodworms should be used sparingly, as MW says, and peas would be a great addition of variety as rhostog has outlined. Bloodworms, in addition to being too rich for the fish's system if given too much can leave really strong oil slicks on the tank water, yet another reason for only occasional use. A good high quality flake food is a good basic to center these other more occasional things around I think.
You are probably very lucky that you somehow established an early habit of the multiple water changes per week that you mention. Without you're explicitly knowing, this has probably been providing the some of the most urgent action needed for what we call a "Fish-In" cycling situation, as MW has pointed out. Here on our beginner forum, you'll be able to learn all of what's behind this "cycling" stuff we're talking about and become an expert on it yourself. Its absolutely core to beginning to know the hobby well. Five platies in a ten gallon will be a significant fish load for a fish-in cycle, so its reasonable to expect that this is going to warrant some serious attention.
While the water changes are the action that's going to keep the water healthy for those fish, you won't know exactly what is or what's not being actually accomplished by the water changes unless you have a test kit, so this ends of being one of the first things beginners need. Most of us like and use the API Freshwater Master Test Kit, which has a series of bottles of reagents and test tubes, with plenty of good instructions and this allows you to measure the ammonia, nitrite(NO2), pH and nitrate(NO3) in your tank water. The liquid-based test kit like this is necessary for the level of accuracy it provides, paper strip tests just not being good enough.
Good luck reading the cycling links in MW's signature and we members will be hear to hopefully answer any and all questions to the best of our ability!
~~waterdrop~~