Error installing oracle 19c database pre-install on oracle linux server 7.6

I'm tryin to install oracle 19c on oracle linux 7.6, I'm required to install oracle 19c preinstall , knowing that this is a fresh install I don't understand why i'm getting these errors : yum -y localinstall http://yum1.stanford.edu/mrepo/ol8-x86 64/RPMS.appstream/oracle-database-preinstall-19c-1.0-2.el8.x86 64.rpm Loaded plugins: langpacks, ulninfo Repository ol7_latest is listed more than once in the configuration Repository ol7_u0_base is listed more than once in the configuration Repository ol7_u1_base is listed more than once in the configuration Repository ol7_u2_base is listed more than once in the configuration Repository ol7_u3_base is listed more than once in the configuration Repository ol7_u4_base is listed more than once in the configuration Repository ol7_u5_base is listed more than once in the configuration Repository ol7_u6_base is listed more than once in the configuration Repository ol7_security_validation is listed more than once in the configuration Repository ol7_optional_latest is listed more than once in the configuration Repository ol7_addons is listed more than once in the configuration Repository ol7_MODRHCK is listed more than once in the configuration Repository ol7_latest_archive is listed more than once in the configuration Repository ol7_optional_archive is listed more than once in the configuration Repository ol7_UEKR5 is listed more than once in the configuration Repository ol7_UEKR4 is listed more than once in the configuration Repository ol7_UEKR3 is listed more than once in the configuration Repository ol7_UEKR3_OFED20 is listed more than once in the configuration Repository ol7_UEKR5_RDMA is listed more than once in the configuration Repository ol7_UEKR4_OFED is listed more than once in the configuration Repository ol7_UEKR4_archive is listed more than once in the configuration Repository ol7_UEKR5_archive is listed more than once in the configuration Repository ol7_kvm_utils is listed more than once in the configuration Skipping: http://yum1.stanford.edu/mrepo/ol8-x86 , filename does not end in .rpm. Skipping: 64/RPMS.appstream/oracle-database-preinstall-19c-1.0-2.el8.x86, filename does not end in .rpm. Cannot open: 64.rpm. Skipping. Nothing to do