The file you attached has been received and reviewed. The sheet named Invoice-Form is a worksheet, not a form in the sense I was thinking (userform). I assume that the information on the Act Data and Accom Data sheets is where you will be getting the accommodation and activity cost figures. Having said that, designing a userform is your next step.
A form with a combobox or listbox for the accomodation costs, a combobox or listbox for the activity cost, a textbox for entering the number of individuals (or maybe one each for both activity and accomodation if they can be different numbers), a submit button, and a cancel button would be my recommendation. To create the form, press Alt+F11 to launch the VBE.
You will find your VBAProject in the list on the left. Highlight the name of your project by clicking it once then select Insert>Form from the top menu. Now you can size the form and place the controls as you desire. There will be coding necessary behind each control to get it to function the way you desire (load the price lists, submit the information, cancel the form).
Format the Invoice-Form sheet the way you want it to look when you print it out. Sending the figures from the userform to the "right" spot on the form will be done once you have decided where the right place on the form is.