Hi Coding Ninja,
If I understand you correctly, you want to enable checkboxes in the data grid 2? I believe the checkboxes were introduced in Mendix 9.24 (https://www.mendix.com/blog/mendix-release-9-24-what-a-ride-it-has-been), so you first need to update to that Mendix version. Also, you need to update (or download) the “Data Widgets” marketplace module. After that, in the Data grid 2 properties pane, you can enable checkboxes in the selection method.
Hope this helps,