I really like commandsigns, and am wondering if there is a plugin like it for portals / for lava and water . Like many other servers do I want to make it so when players walk into a portal,water, or lava a command happens
There used to be a very famous plugin named stargates that accomplished just such a task, but sadly, it has fallen inactive. I'm sure that there are others out there, but I can tell you that this function is usually accomplished by servers using the plugin multiverse. (since it's most common use of such a plugin is usually to teleport between worlds.) If this is the function that you are looking for, I highly recommend multiverse, as it is very easy to set up.
Portal Commands