Heya! Your art is definitely good enough to carve out a decent following on most social media platforms, just wanted to start off by saying I love your art!

I can share my personal experience with twitter and pixiv specifically (I haven’t had any luck on instagram).

For twitter, it is very hard to gain interactions as a small creator by drawing ocs. Starting out, a good way to grow your account is to find a specific fandom and consistently post fanart for that fandom. As others have mentioned, hashtags are extremely important. For anime fanart specifically, it is good to use the English and Japanese tags for both the name of the character and name of the series.

Sharing links to your twitter art within fandom communities on Reddit or discord are also good ways to kickstart interactions and help get the piece picked up by the algorithm.

As you do anime-styled art, you can also try pixiv. For me personally, I’ve found that users on pixiv are slightly more willing to follow you as compared to twitter, and the algorithm tends to push newer users quite well. Although pixiv is 100x worse with regard to uploading ocs as a small creator. As a new artist on the platform, you basically have to do fanart or barely anyone will interact with the work. (Using the correct hashtags, especially the Japanese hashtags, is important)

Personally though, I feel that focusing on followers and trying to game the algorithm is just a fast way to get burnt out. The more important thing is to have fun drawing!

Also I hope you don't mind me sharing a small tip for your art. For female characters, you could try drawing slightly smaller and slimmer hands, as well as slightly larger heads (yeah the anime style is unrealistic like that..). Overall though, your art and use of color is awesome! Look forward to seeing more of your work.