If possible, you could try showing it off outside of itch.io (perhaps on a Discord server, or a subreddit).
If you prefer staying at itch, what you could do is: connect with fellow users, maybe play one of their games or two, give comments, feedbacks and socialize. Not only you might find a potential player, but you would also meet new people, and learn from them. Maybe even learn more about game development in general. If you want them to play your game, maybe try avoiding sending the game link directly. Instead, tell them why they should be interested. There's this thing called 'elevator pitch' where if you could describe your game in maybe under 2 sentences, what would it be? Leave the user/player clueless, but interested.
But if it is your first game, chances are, it would be much harder to show off. There can be many reasons to that, but one I could think of is maybe you're showing off an unpolished product. Maybe there needs improvement for graphics, sounds, game cover, description, play time, mechanic or any part that makes up a 'game'.
If it doesn't work out, don't fret :) You could make another game, that is perhaps a different league from the first one you made. Make your previous game an inspiration and find ways to improve upon that.
I'm not an expert on this subject as there are many ways to promote or share your game, but I hope I helped in some way :)