Goku fires an energy blast straight forward. By holding Up, Goku will launch the blast diagonally into the air, so it can act as an anti-air and is a great way of zoning. The aerial version will launch diagonally downwards. Upon hitting the ground, the blast causes a bit of splash damage; if the opponent comes into contact with this, they still get hit.
You can convert this into a Teleport Kamehameha by inputting the Teleport command during this move's super-pause. This is only possible with this LV1 version of Kamehameha.

A Super anti-air attack; Goku leaps upwards surrounded by energy extremely fast. If he whiffs or it's blocked, the attack ends and he just descends down. If it connects, he will burst into a flurry or aerial punches and ends with a knock-away kick. If you hold forward, the angle of his starting leap-dash changes to a softer angle, covering more ground. With this you can catch an opponent that's in the air but still quite far way.

The second level of the Kamehameha changes the blast into a 20-hit beam, if it's launched right away, that is. You're able to hold down the Punch button to charge up the attack. The longer you charge, the more hits will be added to the beam. Once it reaches its maximum, Goku will automatically launch it and it'll be 40 hits. This version retains the option to launch it diagonally into the air and to launch it diagonally downward from the air.

This works exactly the same as the LV1 version in the first half of it, but Goku ends the punching flurry with a heavy knuckle punch that shoots the opponent down, Goku then teleports next to them and performs a heavy sideways slam, causing a wall bounce. This is unblockable to opponents while they're in the air.

An ultimate version of the Kamehameha. Compared to the LV2 version, it does more hits raw and it can be held (to charge) longer, resulting in an even more damaging attack and you can also float Goku around while charging by simply pressing and holding a direction. Goku leaves the ground while charging thus making this an aerial move. Lastly, you can't direct the beam diagonally upwards nor downwards. It always fires straight ahead.

Goku briefly powers up and then rushes forward. If he touches the enemy, he'll explode into a powerful autocombo, ending with a brutal True Blast Fist and launching the opponent sky-high. Depending if you're on LV1, 2 or 3 of the Justice Bar, Goku will perform a Finisher at the end.
LV1 - 1-Inch Punch.
LV2 - See Ya Spirit Bomb.
LV3 - Ultra Instinct.