Hello Android users!

I'm new to the world of Android and I have a few questions if anybody could be so kind and help me!

Question number 1) I uploaded music on my phone and some of them are listed under "Unknown Artist". After googling this may users advices to down some tag editing apps. Which I did, multiple versions in fact. But all of those tags are correctly edited and list the songs in the appropriate boxes and artist groups. But for some reason on my actual music app, it shows up as Unknown Artist. Help?

Question number 2) Does anybody happen to know how to organise your accounts on the offical Twitter app? I had an iPhone before and when you had mutiple Twitter accounts you could sort them in the order you best use them. Unfortunately I seem to realise that the Android Twitter app just organises them at random. They aren't even alphabatically ordered so I'm confused...

Question number 3) Is there a way to get rid of ONLY WhatsApp's red badge notifications? Because I don't reply all my messages at once and it's bloody annoying constantly seeing how many "unread" messages I have. But after reading around a lot of users say that witn Android I can only disable it via some "Badge Notifier" app on my software itself but that cancels it out for every app? I'm not even sure it's for my phone type so... Again, confused! Haha

If anybody has answers to these three questions, you're saving me from a whole lot of swearing at my phone. Hahaha

Thank you in advance!!