Lead in your soil is a serious issue that can easily be dealt with through the purchase of a lead soil testing kit. The most common occurrence of lead in soil comes from acid rain washing lead off of exterior house paint and into the yard. Car exhaust from nearby highways can also contribute to the problem.
I think you should read the rose growing manuals. These are not simple plants and they require special care. Also, it is better to buy seedlings from trusted sellers. For example here https://dutch-bulbs.com/roses/ . Hope this helps you.