Process of caulking minor gaps between wall or ceiling of cabinetry

Wastlund Custom Cabinetry

[SevenDeMagnus]

Hi. What kind of caulk (or is that the same as sealant. Should I get a sealant instead?) should I tell the staff at the hardware store for the gap between the ceiling and the wall (no molding) for the bathroom (dirt keep falling from the gaps in the bathroom especially) and between the wall and floor (to minimize critters like ants from coming in).

Thank you in advance.
God bless, Proverbs 31