Take a look at some of the threads that already cover this, you can use the search function at the top. Here is one for example – https://appfinite.com/topic/header-cut-off-responsive/ …and there are many more that should point you in the right direction.
Once you get that done, if you still need some adjustments, just let me know.
And please post a link so we’ll be able to see what’s going on.
I create awesome sites for awesome people! Contact me if interested – ericsanchez1585@gmail.com