I have a question i want to learn java and php. So is it ok if I learn it together. Or should learn one first completely than second?

I'd say you can learn both at the same time if you want to

That's two totally differents languages, learn one at a time and the first should be the one you will use first

the problem is that both languages work completely different.
PHP is a script language and java is a runtime language which is why it might confuse you when you learn both at the same time.
My suggestion would be to first learn the java basics and then you can learn both at the same time.