You overwhelm the mind of one creature you can see within range. If the target has 150 Hit Points or fewer, it has the Stunned condition. Otherwise, its Speed is 0 until the start of your next turn. The Stunned target makes a Constitution saving throw at the end of each of its turns, ending the condition on itself on a success.
RollQuest ships the D&D 2024 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.