Arcane Beam

You shoot out a beam of pure arcane energy, and make a ranged spell attack at one creature for 2d8 force damage

Hit and the beam says present in the battlefield miss the beam disappears

everyone within the spaces of the beam and the target of the spell must make a dexterity saving throw against your spell save dc, on success they take half of 2d6 force damage,(only on initial cast of the spell not when you move it)  on a fail they take full . If anyone walks through the beam they then have to make a dexterity save as well but if they succeed they take no damage 

As long as you leave your hand that you cast the spell with open the beam says on the battleground if you hit

Every round you keep concentration you can use your action to pulse energy through the beam again and attack the same target you made the attack roll on, and deal 2d8 force damage without making a attack roll if that target has moved you can close your hands and shoot the beam at the same target as the initial one or make a attack roll on a new target. This attack doesn't cause people within the spaces of the beam to make a save so they take no damage.

The spell ends if the target gets full cover from you or if you end a turn farther then 30ft from the target

When you cast this spell using a spell slot of 3nd level or higher, the Force damage increases by 1d6 damage for the save for each slot level above 2st.