When you make a Strength (Athletics) check to grapple or shove someone, are you making an attack roll? Again, the answer is no. That check is an ability check, so game effects tied to attack rolls don’t apply to it. Going back to an earlier question, the hex spell could be used to diminish a grappler’s effectiveness. And if the grappler’s target is under the effect of the Dodge action, that action doesn’t inhibit the grapple, since Dodge doesn’t affect ability checks.
Can you move through a prone enemy? The prone condition doesn’t override the rule that prevents you from moving through an enemy’s space, unless that enemy is at least two sizes larger or smaller than you. If you do move through another creature’s space—whether a friend or an enemy—the space is difficult terrain for you, and you can’t willingly end your move there. See the Player’s Handbook, page 190–92, for more on movement in combat.
Eating a goodberry requires your action therefor they cannot be administered by someone else to heal an unconscious, incapacitated, or someone otherwise unable to use an action to consume one on their own.