Is it normal to feel like a girl sometimes

I can familiarise with all of this.
It applied to me all of my life so far, but to a much greater extent.
In my younger years I found it fascinating and then, at a ridiculously early age, I realised I actually was a girl and I've been comfortable with it ever since!

I feel like a guy sometimes. Then there's other times where I go completely girly and it scares everyone because I'm usually the tomboy of the group.

If you enjoy it then it's normal for you. My niece likes the fact that her brother cross dresses since she can wear some of his dresses and use his makeup.

Crossdressing?..... Well whatever floats your boat I guess.

I used to do that but I got over those weird habits now. I still laugh like a little girl most of the times though even though I should have a manly laugh.

Well that's a transvestite.
Unless you are doing it not to feel 'normal' to yourself, but to make you feel that a girl is in the house? Like a sexual fetish type of thing.
This can be confusing. But if you enjoy it, don't stop.
IF you ever decide to wear it out publicly, pretty sure you will then be classed as a transvestite, since you then want others to see you.