The KM3NeT Collaboration started the construction of a research infrastructure hosting a next-generation underwater neutrino observatory in the Mediterranean Sea. Within KM3NeT, the ARCA telescope, currently being constructed at the Italian site, will be devoted to the observation and measurement of high-energy cosmic neutrinos. The first two Detection Units of the telescope were operated for several months collecting and transmitting data. From the analyzed data valuable information that validates the detector technology and confirms the unique properties of the Optical Modules, the optical sensors of KM3NeT, has been extracted. Moreover, the new discovery fluxes estimated for the full detector presented in this work confirm that ARCA is an optimal detector to look for Galactic neutrino sources.