The problem is not that’s to easy for you to log in, the problem is that everyone else can try it too. If there are no additional mechanisms in place, such as fail2ban, an attacker will have endless time to try to guess your password or even worse the root password.
Step 1: Create a ssh key
First lets start with the key generation for your client
ssh-keygen -a 100 -t ed25519 -f ~/.ssh/example.com_id_ed25519