While LineageOS is king, you have other flavors depending on your taste:
chipset. Historically, MediaTek devices have been more challenging to develop for than their Qualcomm counterparts due to limited source code availability. Despite this, the community has produced several notable ports: LineageOS (Various Versions) Lenovo A5500-hv Custom Rom
Before attempting a flash, you must gather specific tools to avoid bricking your device: While LineageOS is king, you have other flavors