We will present recent results on galaxy quenching and morphology in clusters and protoclusters detected as overdensities around radio-loud AGN at z> 1.5 from the CARLA (Clusters Around Radio-Loud AGN) survey. The CARLA sample includes progenitors of the present-day clusters are clusters and proto-clusters at 1.5≲z≲3 that are still in the process of assembling. A dedicated spectroscopic survey with HST confirmed 16 clusters (Noirot et al. 2016, 2018). We present their galaxy stellar population, morphology, star formation rate and scaling relation, with the focus on BCG formation and compact star forming galaxies. We discuss the evolution of the passive galaxy fraction in the context of the galaxy formation models.