Travel-proofing myself for Budapest solo trip (advice/help needed)

I’m going to Budapest in two weeks and wanted to know about issues I might have and how to prevent or deal with them. Here’s what I have so far:how are some good ways I

1. Booked flight tickets
2. Booked an airbnb that a friend who lives there recommended, so I think I’m covered on that
3. I’ve read a few posts from people complaining about not having validated their public transport tickets and getting a fine.

**Questions:**

1. I have a transferwise card. Do they work well in budapest? What do I need to do to use them? Do I have to open a HUF account in the app first?
2. Can I buy things with EUR , or is it always HUF?
3. I’m not coming from EU nor US, how can I get a hungarian phone number? I believe this would be helpful for mobile connection + emergencies
4. I’ve heard about the . Are they worth it?
5. What’s the best way to purchase public transport tickets? Is there a daily/weekly pass? Should I buy those or is it better to just buy one-way tickets when I need them?

Are there any other things I should be thinking about? Really appreciate any help!!

Travel-proofing myself for Budapest solo trip (advice/help needed)