

Welcome to the internet! Your system will get probed. Make sure you run as little as possible services on open ports and only high quality ones such as OpenSSH. Don’t freak out because of your logs. You’re fine as long as your system is up to date and password login disabled! Don’t listen to the fail2ban or VPN crowd. Those are only snake oil.
A VPN is probably just as (in)secure as OpenSSH. There is no gain in complicating things. OpenSSH is probably one of the most well tested code for security around.
And why exactly is that more secure?