What is the best oil to use for a petrol Peugeot 207 car?

You didn't tell us the engine type - diesel model mostly has the filter mounted on the engine high up and next to the airfilter.

Petrol models might have a lifetime filter or might have a replaceable type, if so, it is likely underneath just in front of the fuel tank.

Anon, You really should look in your manual or contact manufacturer to find what is considered normal oil consumption. I have never owned a Peugeot, but have had numerous other makes, mostly domestics to USA and Canada and never had to add oil between changes at approx. 5000 Km.s before oil changes.
Peugeot 307 2001 2007 2006 55 1 6 Petrol Oil Consumption Technical matters...
What Are The Reasons of Oil Consumption oilspecifications org
How Much Oil Consumption Is Normal

No valve timing marks on that one - it won't allow you to change that settings.

Have oil pressure checked possible bad oil pump

The drain plug is situated on the final drive casing at the rear of the transmission (plug may need a square or hex drive wrench).

There is no level plug - the correct qty of oil must be measured and then poured in.
If Petrol 1.9 ltrs, diesel 2.0.

The oil is 75/80w.

Fuel filters are only fitted to Peugeot petrol engined cars in countries where poor quality fule is an issue.

Fuel filters are only fitted to Peugeot petrol engined cars in countries where poor quality fule is an issue.

fuel is leaking into the sump
if diesel it will be from the pump and if petrol will be leaking injector seals

is it with petrol engine?
if yes, replace the oil filter, it is better to put Purflux filter

Get it code scanned at auto zone for free they will tell you what it is and reset codes,,,could be oil light sensor