You dont have any other 5v transformers? They’re extremely common and lots of unrelated electronics come with 5v transformers and they are universal so, if you have one that sais it Outputs 5v snd has a microUSB plug, you can use that. For example, here is a transformer that came with one of my Roku’s and outputs 5v - 1a and will work perfectly for powering an esp board.
WLED is 100% my recommendation. When they are on your home network HA shows it in the “discovered devices” I don’t know the extent of control you get but imagine its pretty significant and its a simple thing to configure and add LED’s to.
I buy 5V LED’s and use them with it so its all powered at the same voltage. Otherwise you need a buck converter to step the voltage to wheree you need it.
So, your 100% recommending wled and at the same time you dont know the extent of control there is but, you can only guess?
How can you recommend something you’re not even sure about or doesnt even sound like you use it at all?
I also wouldn’t think of which voltage lights you pick, based on a single and simple factor. If someone is going to do an DIY projects then they’ll routinely need voltage regulators or buck/biost converts because its vety common to use 2 or 3 different voltages for a single DIY project so, its not like they’re avoiding to have to buy a 5 pack of components for and they’ll never need the extra 4 of them leftover.
Some other big considerations that matter just the same or arguably more are if they buy 5v led’s, will they then need to buy a 5v transformer that can push the watts they need and/or will they need extra wire for adding frequent power injections or could they buy 12v led’s and use a 12v transformer they have laying around because they’re much more common and then need no power injections or far feder by using 12v and picking up a 12v-5v buck converter…
Using 5v led’s are fine for little projects but, when multiple strings are required, the difference between 12v and 5v is far more more complicated than whether they need a buck converter so, thats a silly rule to live by and recommend others copy you and use that rule too.