Adding a responsive grid onto a page (without using a Bootstrap theme) [closed]

There are a number of different grid systems available that can be incorporated into WordPress, usually simply by enqueueing the stylesheets for them. Then you can hard-code the HTML by adding div tags with the appropriate classes for that system.

Here’s a good list of different grid system examples:

It may also be worth looking at including and applying jQuery matchHeight, as depending on the application it may also be desirable to normalize row heights.