ELDEN RING SPOILER ALERT
If you run a straight line from the starting location to east, there is a place called Unpassable Greatbridge. There is a site of grace there. When you get closer to the ramparts a scene will play out where soldiers will attack a pack of T-rex hounds. You can hang back and automatically gather all the runes from the ensuing carnage. You can of course speed things up a bit and pick off some unsuspecting foes that get isolated. You’ll easily pick up roughly around 5000 runes per attack. Afterwards there’s good loot to pick up, then just rest at the site of grace, rinse and repeat. Easy rune farming to get your character up to spec.
To get there head southeast from the start to dragon burnt ruins. Open a chest there and you’ll be teleported to a chrystal mine. Run out without engaging and you’ll find yourself in Caelid. Just ride out to the bridge without attracting too much attention and Robert is your father’s brother. With Torrent you can outrun pretty much anything.
I’d suggest heading generally south from the starting location when you’re ready to begin exploring.