If the toilet is leaking from the base it is most likely the wax ring (johnny ring).
Turn off the water supply to the toilet. Flush the toilet and hold handle to allow as much water to drain from tank as possible.Remove the supply line from the bottom of the tank. Remove the two nuts from either side of the toilet, usually underneath a plastic cap. Lift toilet from the flange. Clean wax from flange, and from Bottom of toilet outlet. Replace wax ring with one that has plastic centering flange. Careful when setting toilet back on top of new ring, try to line up the bolt and lower straight down onto them. Lean on the toilet to seat the wax ring. Re- install nuts, supply line, and turn water back on. Flush and fill several times to verify leak is resolved. Careful when tightening the supply line and mounting nuts, do not over tighten. If you have a leak because its too loose just tighten a bit more.
Have fun
Turn off the water supply to the toilet. Flush the toilet and hold handle to allow as much water to drain from tank as possible.Remove the supply line from the bottom of the tank. Remove the two nuts from either side of the toilet, usually underneath a plastic cap. Lift toilet from the flange. Clean wax from flange, and from Bottom of toilet outlet. Replace wax ring with one that has plastic centering flange. Careful when setting toilet back on top of new ring, try to line up the bolt and lower straight down onto them. Lean on the toilet to seat the wax ring. Re- install nuts, supply line, and turn water back on. Flush and fill several times to verify leak is resolved. Careful when tightening the supply line and mounting nuts, do not over tighten. If you have a leak because its too loose just tighten a bit more.
Have fun