You can say "I am Welsh" by simply stating "I am Welsh" in English. In Welsh, you would say "Cymraeg ydw i" (I am Welsh).
If Moira is a form of Mary the Welsh equivalent would be Mari/Mair. Names aren't really 'translated' though.
'Our Friends' in Welsh is 'Ffrindiau Ni' :)
To say "your house" in Welsh, you would say "eich tŷ".
Cymraeg
"Na" is the word for "no" in Welsh.
"y diwedd" is how you say it in Welsh language.
In Welsh, you would say "Rwy'n cytuno" to say "I agree."
Welsh dragon in Welsh is "draig Goch".
You can say "it's nice" in Welsh as "mae'n braf."
Daeargi Cymreig
"She is" would be "mae hi" in Welsh.