Honestly, I prefer when authors put story titles, because when I really like a chapter, a couple weeks later I can still be able to recognise it by the title (because it's related) and not have to browse through all the earlier chapters, so it's easier for me. But that's just my preference :)

My chapters just have one word titles sometimes they aren't even related to the actual chapter. But I prefer a small title, like, one word hahaha like "Breathless" but sometimes it gives it away, but that...it's up to you, I prefer chapters with titles though...

Why not just say "Chapter 1" or "Chapter One" that's what I do if I decide not to use titles.

Id say do numbers but add a little quote from the story that has significance to it. That's what I do :) like "01. 'Happy birthday doofus here's your gift'" or something

You should but titled chapters like you know "chapter 1 Happy Birthday..." Something like that

I think having #'s is better because as you said it gives the chapter away. And I hate that, I wanna be surprised, not spoiled. And it seems authentic to me, having numbers. It reminds me of old books written by middle-aged English writers (not to be mean. I like that actually~). And of course, when you try to come up w. a name for that chap. it holds you back like 3 days from updating! Making little things so complicated and over-thinking them.. it bugs me, yet I do it ALL the time xP

It's easier for your readers to find a chapter if you keep the words in there.
They might want to reread a certain chapter and your chapter title could be the keyword that helps them find it. ^^

Do something that you want to do. Maybe try something that wont be too reviling but will leave us readers hanging! Maybe you can use numbers and words? IDK, anything you want!!

001, 002, 003 goes better!