The homebrew cantrip Stormwalk looks powerful, probably too powerful.
Generally, a cantrip is roughly equivalent to martial melee attack, so something like d10, then adjusting for other costs and benefits.
1d6 to everyone around the caster − an area damage − is already verging on too powerful. None of the Players Handbook cantrips grant this. The Sword Coast Adventure Guide has the Swordburst spell that grants 1d6 force damage to everyone within 5 feet, and no other effect. But both Xanathars and Tashas seem to quietly omit it from their spell list updates. Likewise, Thunderclap is only in the Elemental Evil Players Companion. It deals 1d6 thunder damage, but again, Xanathars and Tashas seem to quietly omit it. If I recall correctly, 4e has an area damage cantrip that deals 1d4 damage, and no other effect. An area damage cantrip is a big deal, and even the ones that were in 5e seem to fail to remain official.
How do you figure? The way I see it, an AOE cantrip is only ever better than a melee cantrip when it hits two targets. In terms of melee cantrips we get Primal Savagery which is 1d10 damage. So, immediately that tells me that hitting a single target in melee is 1d10. Dropping it to 1d8 for an AOE is a little too much maybe, but 1d6? That seems reasonable for hitting 2 to 3 targets, and you never want to be a cantrip user with more than three enemies around you unless you are an Eldritch Knight.
Now granted, this cantrip does help with the single greatest threat to AOE cantrips, in that it helps you get away from the crowd that you hit, but that's why I think it is fair to reduce the damage to a max of 2d6. However, there is another consideration I'll get into in a second
Regarding speed, an entire feat is required to grant +10 speed. But in this case, the cantrip needs to spend an action in order to move the extra speed. But in this case, it is like the Dash action, but more powerful because of the +10 speed.
Um... the dash action is far more powerful. It is (likely) a +30 to movement, where this is only +10 ft. You don't get to move your speed as part of this cantrip. I was more looking at Longstrider, which is a permanent +10 movement as a 1st level spell, but since this was every action and only worth 1/3 of the dash action, I felt it wasn't too powerful.
Then causing advantage or disadvantage is itself a big deal.
Yes, causing advantage or disadvantage is a big deal. But remember that pin? If the goal of this cantrip is to provide something to help escape a crowd, you have to consider the other actions at your disposal. Particularly, disengage. Which doesn't just grant disadvantage on AoO's, but flat immunity to them.
This is why I think the disadvantage exists. Because to use a 5ft AOE you need to be adjacent to enemies, and to use the +10 ft of movement, you need to actually move. Using it then moving towards enemies was worse than just dashing. But if you want to guarantee no damage and run away, you disengage. That's why I think this was designed to fit into that middle ground. You want to run, but you want to deal damage, so you risk the AoO, but get a boost to running.
Stormwalk seems certainly broken.
A fix here is a nerf.
Stormwalk
Action to walk +10 and you can spell attack one melee target dealing 1d6 lightning. Additionally, the action can push along with you an unattended light object that is within 5 feet, and harmlessly billow hair, clothes, and other objects.
A cantrip such as this is useful for chasing or fleeing. One can cast it without needing to injure anyone, in order to improve a Dash, traveling move 30 plus an additional action 40. An the electrical damage is sometimes useful. The pushing is rarely useful but is a flavorful ribbon.
Something like this anyway.
So.. I don't think this is doing what you intend. I'd say getting to dash +10 ft and getting to attack is far too much. The original spell was just taking you from moving 30 ft to moving 40 ft. This gives you 70 ft of movement, making it superior to the dash action which lets you move 60 ft. Then you also get to attack. That isn't a nerf, that is a massive buff.
Also, the push a light object is basically useless. Just use your item interaction to grab it if it matters for keep away purposes.