If you mean 'do' like in 'door' it is written ド in katakana and ど in hiragana and pronounced just the same. If you mean like in 'to do' it is written ヅ in katakana and pronounced /dzu/ and づ in hiragana with same pronunciation.
Dude is pronounced "dood" or "dewd".
you pronounce it 'Dude-ay'
to
Nabigeetaa.
washi
kore
osutoraria
tsuki
maikaru
Steevann
yoru
saigo