Whenever I try to place command block or redstone it dissapear. Also i can't activate TNT. Anybody knows a solution??
Those items are sadly not supported by pmmp (yet). If you don't need plugins and such, you might be happier with the official Minecraft server.
Well, considering there is no redstone, you won't get much use out of command blocks. What are you planning to do with your server?
Just playing with family. I would like setup in house something like insta healing, giving food or teleporting to other places maybe.
I think the official dedicated server will fit you best as it provides complete vanilla gameplay unlike PMMP which lacks some features like Mobs and Redstone but offers plugins instead.