You will need to speak to someone in the system in PA and get them to explain this to you at length. If you cannot reach the call center, go on line and submit your question or call the technical support office of unemployment and ask them. PA will be a bit different than anyone else and will have certain standard practices and definitions of their terms such as sideline business.
Usually, very generally, some self employment is okay in most situations, in other words, the income is okay for you to make, since unemployment insurance is NOT based on your income, but you must also be making a very diligent job search, and be willing to swear weekly that you are fully able and available for other full time work.
In other words, you must cooperate fully with all job seeking activities, be able to accept any job referrals you are offered, even though you may be running a sideline business. You can't turn down anything saying you are working twenty hours a week or something at your sideline business or self employment. When your business reaches the point that you are too busy to do job seeking and don't need another job, you are no longer eligible for unemployment. Again, talk to your state unemployment office there.