Minecraft players connecting with others in 2021 #1 - Java To join another player's world on Java edition, which is for PC, the host must open their world to LAN.

Local LAN play- it’s best for the players in the same Wi-Fi network. No server is required. Online Servers- host or join the dedicated Minecraft server for the persistent multiplayer experience.

Although Minecraft's Java and Bedrock Editions are quite different, it's still possible to convert an existing Java world to Bedrock if you don't mind there being some differences to the world ...