Before you start pulling things apart I'd recommend you start with the
basics.
First clean down (degrease) the whole engine top to bottom. After that keep
an eye on it every day. Oil, like most  everything else on this planet is
subject to gravity. When you have a leak it will drip down the engine,
sometimes collect, in a horizontal flat spot and then drift down to soak the
lower most point, the oil pan, and then blow back from there. Cleaning the
engine can allow you the opportunity to see where the leak originates.
Some of the more likely spots are the valve cover gasket, balance shaft
seal, crankshaft seal, oil pump seal and less often the cam seal. You can't
see the crank, balance, oil pump or cam seal without removing the upper and
lower timing belt covers, but look for the oil to be coming from the bottom
of the lower cover if it's either one of them.
The best way is to put an ultra-violet dye in your oil and with an
ultra-violet lamp (if you have access to one) spot where the oil exits the
engine from.
Good luck.
Howard

automatic transmission fluid is stained red so you can tell leaks apart
from engine oil leaks.  that's a 2-second diagnosis and an oily finger.