Hmm ... You use the words, "Wapendwa" and "tafadhali"(inflated expression). It means that those are polite sentences. So, at least "ninataka" instead of "nataka" and "ukiweza"(or "mkiweza", a plural form coresponding to "Wapendwa") instead of "unaweza". I think the below example is more simple and better. "Mimi ninataka kujifunza Kiswahili. Kama ukiweza kusaidia hata mwanafunzi (wa hatua ya kwanza) kabisa, naomba unipigie simu. Namba yangu ni xxxxx". Well ... if a student would write like that, she/he might not need a teather, though.

Mimi nataka kujifunza? Kiswahili I'm not sure the verb form here...