I`ve tried to create my room, but it just says everytime "unable to create new room, please try again"... I`ve repeated it many times, but it didn`t work. Could somebody please help me?

its happen because there are many rooms, you have to wait maybe 5 to 15 minutes to create (sometimes more).

Problem is solved. Excuse me

Oh, another problem! I can`t launch a mod... I`m writing as in instruction -

/set mod twinsword1.tbm

but it launches aikido.tbm
Could somebody explain me, why? Or probably I do something wrong?

You might not have the mods.
Get them from the mod folder of Toribash 3.69

there isnt a twinswords 1 there is Twinswords2 and 4 but not 1 or 3 and it doesnt work for me either

I had the same prob to lol