What are you posting mostly, Shorts or Videos or both?
If both in what ratio?
Second question, Did you initially boost subscription to get a said number for example, 100 subs or not?
And, My advice would be to make your Thumbnails as professional as you can get.
If you cant edit them yourself or hire a designer.
You can do it on Canva.
To get Canva Free for 1 year. You can use @SAIYAN invite from here : His thread