Hello,
01. Which image do you want to decrease the size of?
02. Secondly, the Sidebar under the Wishlist only appears for the Logged In Users not for the ones which are not Logged In. For the Account Sidebar hiding on the Wishlist page for the Logged In Users, please try using the below Custom CSS code and paste it to Dashboard >> Theme Settings >> Custom CSS >> Global CSS section:
.page-id-118 .wd-my-account-sidebar {
display: none !important;
}
.woocommerce-MyAccount-content {
flex: 1 0 100% !important;
max-width: 100% !important;
width: 100% !important;
}
03. Go to Theme Setting -> Shop -> Cart -> enable the option Update cart on quantity change.
04. Go to Woodmart -> header builder -> edit current header -> Configure account setting. Set the form display dropdown.
Best Regards.