Help with Traditional painting {beginner]

First of all, what kind of paint are you using? It looks similar to acrylics and watercolour but not quite the same.
If it's acrylics I'd start with the darkest tones first and go lighter from there. But I'm not sure what you mean by 'realistic'. You mean like a photo or can it be painterly?

The face looks good so far! Don't forget that eye whites aren't pure white and a darker skin tone can make them look less realistic because they'll pop out a lot.

@Anlly Ooh, traditional, I like it.
Mm, what I learned from a workshop the past weekend, it's best to start with the darkest darks and go up in value/tone from there! Block in shapes of the subject matter and fill it in with the closest value you see/think. As far as going for realistic or not, it's up to you! So far it has an interesting feel to it, so I don't think it's necessary to push for a realistic approach. But, it's up to you if you want to push for that, though!