Only expose applications to the Internet if you have a good need to. Otherwise, use a VPN to access your home network and get to your applications that way.
If you are exposing them to the internet, take precautions. Use a reverse proxy. Use 2FA if the app supports it. Always use good, long passwords. Login as a limited user whenever possible, and disable admin users for services whenever possible. Consider an alternative solution for authentication, like Authentik. Consider using Fail2ban or Crowdsec to help mitigate the risks of brute force attacks or attacks by known bad actors. Consider the use of Cloudflare tunnels (there are plusses and minuses) to help mitigate the risk of DDOS attacks or to implement other security enhancements that can sit in front of the service.
What might be a good reason for exposing an application to the Internet? Perhaps you want to make it available to multiple people who you don't expect to all install VPN clients. Perhaps you want to use it from devices where you can't install one yourself, like a work desktop. This is why my Nextcloud and Calibre Web installs, plus an instance of Immich I'm test-driving, are reachable online.
But if the application only needs to be accessed by you, with devices you control, use a VPN. There are a number of ways to do this. I run a Wireguard server directly on my router, and it only took a few clicks to enable and configure in tandem with the router company's DDNS service. Tailscale makes VPN setup very easy with minimal setup as well. My NAS administration has no reason to be accessible over the internet. Neither does my Portainer instance. Or any device on my network I might want to SSH into. For all of that, I connect with the VPN first, and then connect to the service.
Only expose applications to the Internet if you have a good need to. Otherwise, use a VPN to access your home network and get to your applications that way.
If you are exposing them to the internet, take precautions. Use a reverse proxy. Use 2FA if the app supports it. Always use good, long passwords. Login as a limited user whenever possible, and disable admin users for services whenever possible. Consider an alternative solution for authentication, like Authentik. Consider using Fail2ban or Crowdsec to help mitigate the risks of brute force attacks or attacks by known bad actors. Consider the use of Cloudflare tunnels (there are plusses and minuses) to help mitigate the risk of DDOS attacks or to implement other security enhancements that can sit in front of the service.
What might be a good reason for exposing an application to the Internet? Perhaps you want to make it available to multiple people who you don't expect to all install VPN clients. Perhaps you want to use it from devices where you can't install one yourself, like a work desktop. This is why my Nextcloud and Calibre Web installs, plus an instance of Immich I'm test-driving, are reachable online.
But if the application only needs to be accessed by you, with devices you control, use a VPN. There are a number of ways to do this. I run a Wireguard server directly on my router, and it only took a few clicks to enable and configure in tandem with the router company's DDNS service. Tailscale makes VPN setup very easy with minimal setup as well. My NAS administration has no reason to be accessible over the internet. Neither does my Portainer instance. Or any device on my network I might want to SSH into. For all of that, I connect with the VPN first, and then connect to the service.