My Bulgarian is very limited but since no native speaker has replied yet, I will try to help you. "How do you say in Bulgarian ..?" is "как по български ..?" which means literally "How in Bulgarian". There is no Bulgarian translation of "to speak" because the language has no infinitives. You would say говора which means "I say" or "I speak" If you want to say "I want to speak English", you would say "I want that I speak English" - искам да говора по-английски
Note also that the ъ which in Russian is an unvoiced letter added to consonants to change the pronunciation, is a vowel in Bulgarian pronounced something like "u".