Otis Carpenter opened a medical practice in Alexandria, VA

Sept 1 The business received $33,000 cash and gave capital to the owner.

Sept 2 Purchased medical supplies on account $7,000

Sept 2 Paid monthly office rent of $3,700

Sept 3 Recorded $10,000 revenue for service rendered to patients on account.

Sep 1. Where did the cash come from?
If from a loan, then the entry is:
Debit Cash for the amount
Credit Notes Payable for the amount

If the owner invested the cash, then the entry is:
Debit Cash for the amount
Credit Owner's Equity for the amount

Sep 2:
Debit Medical Supplies for the amount
Credit Accounts Payable for the amount

Sep 2:
Debit Rent Expense for the amount
Credit Cash for the amount

Sep 3:
Debit Accounts Receivable for the amount
Credit Service Revenue for the amount

I am assuming this is a for profit company.

Medical companies usually follow Non-profit or Govenmental accounting.