I’d rather not. I’ll help you do your work. I’ll help you make dinner tonight.
I’ll help you cook dinner tonight. Let me help you with that. Can I submit this
report tomorrow? Do you mind if I submit the report later today? Let me help you
with the reports. Can I work with Maria today? Do you mind if I go early today?
I have a doctor appointment. You should pay (for) it now because you may/will get fine.
You should come on time to work.
It's okay to start a sentence with "because," but it has to be a complete sentence. Ex: Because I have a doctor's appointment, I have to go early today. This is acceptable.