안녕하세요! 저는 베트니입니다(or 예요). 저는 미극 사람입니다(or 이에요). 저는 스 물 여 덟살입니다(or 이에요)
It is a good start! Just remember only spaces between words, not syllables. And remember to end the sentences (입니다, 이에요/예요, 이야(informal) ~ is/am/are).
살 = counter for age
저는 not 자는
Also, you probably don't need to use the pronoun (저는) in every sentence. Pronouns can often be dropped. :)