Introduction

Namaste.
Mero naam Charlotte ho.
Timi sangha bhettera khusi laagyo.
Mero ghara England ho.
Ma bidyarthri hu. Mero Ma doctor padhchhu.
Ma bolnu birarmi Nepaali pardaichu.

You probably wanted to say:

Ma raamrari Nepali bolna Padhdaichhu. 

I am studying/learing to speak Nepali nicely. 

I mean: I am learning to speak good Nepali. 

Mero bhai : my brother so mero is possesive. 

I think Ma medical science(or medicine or daktari) padhdai chhu would be better.

Keep it up, Charlotte. 

Namaste.