SSH permission Denied

Hi

2 weeks ago I format my pc to ubuntu 17.10.Then I try to log in my server but it refuses.

• I create rsa keyin my pc. and put it from droplet panel first but it refuses again (permission denied) then tried DO ssh setting (how to use ssh key) , it refuses again
• I changed ssh_config, add password authentication pubkey auth, rsa auth, it refuses permision denied
• I remove .ssh folder from root and user in droplet, it refuses again

output /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed /usr/bin/ssh-copy-id: INFO: 2 key(s) remain to be installed – if you are prompted now it is to install the new keys Permission denied (publickey).

or

debug1: Offering RSA public key: /home/selo/.ssh/id_rsa debug3: send_pubkey_test debug3: send packet: type 50 debug2: we sent a publickey packet, wait for reply debug3: receive packet: type 51 debug1: Authentications that can continue: publickey debug1: Offering RSA public key: /home/selo/.ssh/id_rsa debug3: send_pubkey_test debug3: send packet: type 50 debug2: we sent a publickey packet, wait for reply debug3: receive packet: type 51 debug1: Authentications that can continue: publickey debug1: Trying private key: /home/selo/.ssh/id_dsa debug3: no such identity: /home/selo/.ssh/id_dsa: No such file or directory debug1: Trying private key: /home/selo/.ssh/id_ecdsa debug3: no such identity: /home/selo/.ssh/id_ecdsa: No such file or directory debug1: Trying private key: /home/selo/.ssh/id_ed25519 debug3: no such identity: /home/selo/.ssh/id_ed25519: No such file or directory debug2: we did not send a packet, disable method debug1: No more authentication methods to try. Permission denied (publickey).

what must I do?

note: I read all question about ssh in do

thanks