You can also do what vs dev suggests programmatically by assigning the style with Javascript by iterating through the columns and setting the td element at a specific index to have that style.
<td style="visibility:hidden;">
or
<td style="visibility:collapse;">
The difference between them that "hidden" hides the cell but it holds the space but with "collapse" the space is not held like display:none. This is significant when hidding a whole column or row.
If you want the column number to be dynamic, you could do that using querySelectorAll or any framework presenting similar functionality, like jQuery here:
CSS (Cascading Style Sheets) will cascade attributes to all of its children. This means that *:nth-child(1) will hide the first td of each trAND hide the first element of all td children. If any of your td have things like buttons, icons, inputs, or selects, the first one will be hidden (woops!).
Even if you don't currently have things that will be hidden, image your frustration down the road if you need to add one. Don't punish your future self like that, that's going to be a pain to debug!
My answer will only hide the first td and th on all tr in #myTable keeping your other elements safe.
use .hideFullColumn in table and .hidecol in th.You don't need to add class in td individually as it will be problem because index may not be in mind of each td.