Where can I find or buy 4 shovels and 4 pickaxes? I need them for a mod quest and I cannot find them anywhere i tried going to random different mines but that didn't work.

You mostly find them in random clutter or at farms.
I think that the Three brothers Trade Goods sells a few or have them sitting in open barrels. Check every farm you see, there should be a few lying around.

As Ni! has mentioned Three Bros. does have both picks and shovels, and Jensine in the Market District also has a few of each. But since they have no value these items will not be available for purchase (unless the mod you have changes this).

Some other areas:


That should get you what you need.

Or just look in the barrels and sacks and crates in the Market District.