Hi @youhhou, welcome to Steemit. I like your photos.
There are several photo contests on this platform. I don't know if that's for you, but mostly you have just to give the post the tags according to the contest. Here is an overview:
https://steemit.com/steemit/@gabyoraa/useful-information-for-new-and-old-photographers-on-steemit
I found it good to begin with, and to look what others have done with the same hashtag.
There are also accounts promoting photos/original content like @yourluckyphotos and @photoworld, just check them out!
Have fun!