Various: Customer Acc's & Cart Options

Site URL: https://heptagon-ocelot-y6ec.squarespace.com/

Hello, 

I hope you the forum doesn't mind if I ask three questions, they are related. 

Firstly, my client would like to add a total cost figure (in pounds and sterling) on the cart icon. Currently, it displays the number of products in the cart. Is there a way of changing this?

Secondly, I've added the option for 'Customer Accounts' however, I would like to change the text from 'sign up' to 'log in'. There doesn't appear to be an option to change this. 

And finally, I'd like to add a 'back to shop' function on the cart checkout page. 

Thank you in advance. 

Jason

Q2. I guess you can. If you share link to your site, we can give the code to change "sign up" text

Q3. Cart page (/cart) or Checkout page (/checkout)?