Manager at an Apartment took my couch

The manager at my apartment took my couch off my balcony....
and she did not leave any notice when she came in or when she left...

[OHlandlord]

Not all states have a statute requiring prior notice to enter your premises. You will need to look in your state's LL-Tenants laws to see how much or if prior written notice is required to enter. What was the reason to remove the couch? Was it placed there in violation of a rule (like "No interior furniture may be placed in exterior areas.")? Call the LL and ask what happened to your couch and ask for it back. If it violated a rule, she has the right to issue a violation notice and require that it be removed. If you failed to honor the violation notice, she could then notify you that she would cure the violation by its removal. But she cannot merely come into your unit and remove it without prior notice to you. She cannot remove your personal preoperty from your leased area without notice.

Would those issues be in most lease agreements as well, or not actually in the lease?

[OHlandlord]

The required amount of notice is usually a state statute found in your state's LL-Tenant laws. In some states, there is no statute on this. Occassionally, it is addressed in a lease, and the LL will write how much notice he/she will provide before entering. There are even a few places where this notice information can be found in local (city) code or in case law which sets a precedent. Start by looking in state law.

Rules, like the exterior furniture prohibition can be found either in the text of your lease or in some set of rules that govern the property (usually given to you at lease signing or posted in the office or common area). If you are unsure of any set of rules at your property, ask the manager/LL for a copy of the rules that govern the property (sometimes called a set of rules for tenants).

Good advice, thanks for the input all.