Q.damage to peach tree bark/fixing
Got damaged by lawnmower last summer. Now it is seeping, clear gooey liquid but does not have missing bark. Do not know what to do.

I think you should explore the possibility that you have a peach tree borer - it doesn't hurt to check and be on the safe side. Peach borer larvae may have found an advantageous avenue into your tree through the wound that was incurred by your lawnmower. When the borers are present trees will exhibit an oozing, clear gum-like sap. You can read more about peach tree borers and a recommended course of treatment at the following link:
https://www.gardeningknowhow.com/edible/fruits/peach/peach-tree-borer.htm
Injury, such as those sustained by lawnmowers, can also cause sap to run from the tree. For more information on repairing damaged tree bark, please visit the following link:
https://www.gardeningknowhow.com/ornamental/trees/tgen/repairing-tree-bark-damage.htm
For more information on growing peach trees, please visit the following link:
https://www.gardeningknowhow.com/edible/fruits/peach/peach-tree-care.htm