How to remove extra slash in comments link? (Newbie)

Hi, this is a brilliant piece of work but I need a bit of help please.

I’ve had to set my home page as https://www.myhomepage.com/blog/index.php as my server isn’t (yet) recognising index.php as the home page. What happens is that the link to comments and other items on the page have an extra slash in them, which makes them unworkable. They come out like this:
https://www.myhomepage.com/blog/index.php/?p=1#comments

Also, the “view site” link on the admin page goes to https://www.myhomepage.com/blog/index.php/

I’ve searched these pages for a clue on how to fix both of these, but I’m not able to find a solution. The first problem is the most critical.

Apologies if this has been covered elsewhere, but if anyone can help it would be great.