BROOKLYN THEME, mobile grid 2 columns error

[goldfoxnl]

Hi!

I use the Brooklyn theme. I don't know a single thing about coding, but I wanted a double column for my website. I think I pasted this code into my website:

Now this happens:

Can someone please help me fix this?? I don't know how to!

[PaulNewton]

Site url and storefront password if any.

Rollback your theme files https://shopify.dev/tutorials/customize-theme-troubleshooting-roll-back-to-older-version-of-theme

[goldfoxnl]

My URL is www.goldfoxnl.nl

No password 

What I meant, is that I want my mobile grid view with 2 columns but it is bugging

[PaulNewton]

looking at a couple of products nothing looks wrong. 

Goodluck.