There is no requirement that an executor must accept the executorship role, even if it was agreed to do so. But relinquishing executorship should be done as soon as practical if you don’t wish to act and have not dealt with the estate. You can resign your appointment as executor by renouncing your right to probate of the deceased’s will, that is you renounce probate.
Among the first considerations in making a will is considering what we own. Only property owned personally can form a deceased estate and be disposed of by will, but it is easy to overlook that property thought of as ‘ours’, is legally in another name. It pays to check who owns what, that which is not in your own name, is not yours to give by will.