I've walked rather long path before I'be found the name that I use everywhere now.
I started as Decoy Ace when I was a teenager. I've thought that sounded great and mysterious. I feel so ashamed about it now XD
Then I've tried Illex. It sounded nice, but I once googled it and it appeared none of my works were found, but some fishing stuff. I didn't want to get associated with some squids or whatever XD
Then it was LettyDD
I used it for long time. Name "Letty" was nothing special, but "DD" helped me to make it more unique. And that was enough to he googled, though there were some unexpected results.
Then bad things happened and I had to change my pen name. I used the same formula and became NetsaTC. And it worked the same way. But that was the first time I had to feel the pain of changing ALL my accounts. My subscribers were very confused, when they found some unknown artist in their list. And some of them freakened out and unsubscribed without checking my page.
And finally I became Airis Kiahin. I like this name most of all. It is more mature, it sounds nice and it is easier to remember than two symbols which mean nothing for anyone but me. Moreover, name+surname give you more chances to make something unique. And it googles easily. I'm not a famous artsit, but Google finds all my social pages and many arts.
However, I think name is just a part of your total appearance. People will recognize you because of your name, your avatar, your art style and even your speech manner.
So just pick your name wisely, but don't get too stressed about it. It's OK if it is not absolutely unique, but the main thing is to stick to it for as long as possible si people could easier recognize it