A few corrections.
nofri! ]nane sep`hmot! .
nane is not a true verb. It is really an adjective. So you do need to say 
}ouj. Also, without a pronoun, 
Sephmot   is the imperative tense. In other words, you are telling someone "Thank" or "Give thanks" (better English). You need to write 
]sep`hmot `ntotk.. You could get away with 
Sephmot   in colloquial talking, but not in proper Coptic.
]er jout `nrompi
I can tell you're translating from English. I am twenty years old, is usually written as 
Ouontyi jout `nrompi. Literally, "I have 20 years"
 ][i`cbw `eoucyini.
This means I study from a doctor. I think you meant, I am studying medicine, which would be 
][i`cbw `n]metcyini[/color]
 ]beri `epaima. 
I am not sure if you can say 
 ]beri  because 
beri is not a verb. You should use 
Aierhytc `mberi `mnai. This is equivalent to the Arabic, "Bedat hena gadedan" 
 ][i`cbw ]nis] `n`acpi `nrem`n,ymi alla ]ka] houo an. 
The verb 
 [i`cbw  needs a participle to direct us to what you're learning. You need to write 
 ][i`cbw `e]nis] `n`acpi. The same with 
 ka] . You need the participle added. It should be 
 ]ka] `nhou`o an.]ouas `ntanane `e]nou.
As described before nane is not a verb. You could say 
}ouws `eernis] `e]nou.  I wish to become greater more than now (also can be I wish to become better than now)
Very good work.
George