Hi Racheal,
You can use the following code to make the contact form 100%.
.wpcf7-form-control {
width:90%;
}
and to adjust the menu in one line put the following code into the custom css.
@media screen and (max-width:1000px) {
.main-navigation li {
margin: 0 0 0 1rem;
position: relative;
}
}
Please use the code in the child theme css.
Thanks.