In our theme currently not having font size change functionality. If you to change it then send us font size we will change it for you.
We have solved your contact form error. We have set form as you want. Please kindly check it.
In services section, Same size of content box is set for all services box. You can not set it small. If you want to set small box of size then you may add 8 or 12 services and set number of services by Appearence >> Customizer option.