N5 — outside your level filter

so; that's why — draws the consequence of what was just said

明日あしたは朝あさ五時ごじに出でるんだ。だから、もう寝ねるね。

ashita wa asa goji ni deru n da. dakara, mou neru ne.

I'm leaving at five tomorrow morning. So I'm going to bed already. casual

だから、その店みせは今日きょう休やすみだって言いってるでしょ。

dakara, sono mise wa kyou yasumi datte itteru desho.

Like I said, that place is closed today. casual

Variants

ですからdesukaraformal
the polite form — service speech and spoken announcements; same sentence-initial position, and it changes nothing but register.

だから

だからdakaraN5neutral