you can't use "open to lan" for multiple reasons:
1. I don't think crossplay is in minecraft yet, at least for bedrock edition of course
2. open to lan will only work for devices within i think a 1 mile radius...meaning that those who are further away from the network wouldn't be able to join
3. Not everyone may have the same version of minecraft (java and/or bedrock edition) Bedrock and java players (i dont think) can crossplay since they are somewhat different as in game mechanics and updates
thats why i suggest you create an official server (NOT LAN) so that everyone can join. If anything, i have a couple of friends, and they can help me with it if you rather me make it....i dont have minecraft at home yet, but i plan on getting it for ps4 and/or my laptop on java....
in other words, i can create the server, but everyone would have to be on java or console if crossplay is indeed not in minecraft yet