Are there clear parking restrictions? By this I mean yellow lines or prominent signs?
The court process works like this, if it is sent to court after 14 days have expired you will receive a claim form. You have a fe choices (1) pay the fines, and court fees and potentially 8% interest. You will have a short period of time to pay and payment at this stage will not show as a ccj on your credit file. (2) defend the the claim. Your stance of not being happy to pay to park outside your house is an insufficient defence. The defence must be on the ground that the ticket is invalid, I.e not in accordance with regulations or statute. (3) don't pay. Option 2 could result in a ccj if your defence is invalid. Option 3 will result in a ccj.
You can dispute now if you have valid grounds.
Alternatively try to negotiate paying less as the debt is approx 3 years old. The debt collector may take an offer but if this debt is already showing in your credit file part payment will only show as a partial settlement.
Do you have any further questions or queries? I am happy to assist further.