Based on comments, you want to install an unswitched outlet next to the switch. Since you have confirmed that you have neutral in the box, that should be straightforward:
Unless the circuit is already GFCI protected, you MUST use a GFCI receptacle. The following is based on a typical GFCI receptacle.
Add two pigtails on the incoming hot wire with a wire nut. Connect one to the switch (where the incoming hot was previously connected) and one to the hot screw on the LINE side of the receptacle.
Add a pigtail to the neutral bunch and connect it to the neutral screw on the LINE side of the receptacle.
Add a ground wire to the rest of grounds and connect it to the ground screw on the receptacle.
Nothing goes on the LOAD side. Those terminals are covered with tape, leave the tape on there, it will save you unlimited grief.