see here: Speech Corpus

>2- is it a necessary to record files bymyself??

If you want to... no sure what you are asking

>3- should i use test files which i recorded by myself ?because at my project

>i used ready files for test which i do not record?

depends what you are trying to do...

>i do not understand adaption and why we need it?

see here: Using HTK & Julius

>4- the website contains only 30 files for training ,do you think they are

>enough for a good training?

I am not sure what you are talking about... the VoxForge tutorial shows you how to train an acoustic model yourself, so you can see how the process works.