Does not come with Google Play Services pre-installed; you must flash a separate GApps package (like NikGApps) if you need Google services.
Now for the main event. Here's a generalized guide on how to install a custom ROM on your Oppo F11 Pro. oppo f11 pro custom rom xda best
Power off your phone, then press and hold the Power + Volume Down buttons (or the key combination specific to your device) to boot into OrangeFox Recovery. Does not come with Google Play Services pre-installed;
– A great balance between performance, stability, and customization. It is based on LineageOS but includes a plethora of customizations and optimizations to tailor the ROM exactly to your liking. oppo f11 pro custom rom xda best