Newbie - website help please !

[#1]

Hi folks,
I'm new here and I'm hoping someone can give me a push in the right direction.  I have a standard webspace/hobby website which seems to be working ok apart from the "contact" page where you try to send a contact/comment back.
This is an entirely new area to me so I just followed a template page which seems to use a php script to do the actual sending of the comment to a gmail address.   My trouble is that when I try this from Chrome or Edge all that happens is that the php script downloads to my PC, which isn't helpful !  I'd like to be able to fill in the comment and then send the email by just clicking on a "submit" button like the professionals do.  This is the page I'm struggling with;
http://www.martley.plus.com/contactus.html
So is there an approved method of doing such things on Plusnet servers or is there a FAQ somewhere that I can look at ?  
TIA,
Brian  
[Moderator's note by Mike (Mav) : Link fixed]

[#2]

Unfortunately standard webspace does not support PHP or Perl scripts which are used to provide this functionality. Until a couple of years ago a centralised script was provided to support this requirement, but that was withdrawn due to security concerns.
There is a long topic concerning this here but the post which provides a way forward is Reply #46.
Hope one of the options mentioned there helps.
David

[#3]

Hi David, and thanks for responding so quickly.
I didn't realise this was an old topic or had been up before  so your post is very helpful, especially highlighting #46 as a way forward.  I read through the complete thread but must admit some of the details are losing me. As I said, this is new to me, my web skills are Frontpage98 vintage so that doesn't help !
As this is just a hobby website I think I'll look at the free options listed and see how they work out.  And I'll spend a bit more time looking through past forum threads  ! 
Thanks again,
Brian