Purchase order custom field setting

I have created a purchase order with a customer field “CURRENCY” and found the column width too wide:

I have search for solution for this in forum and found below:

However, I am completely new on html coding and tried to create a new theme using the built-in Plain theme but is struggling on how to do the amendment, as I failed to locate which phrase in the code need to be revised with which phrase.

Another problem is that I have created 2 custom field for signatures, and want to move the second one (originally below the first one), to the right hand side of the first one:

8J%5BSBLNGK%EF%BF%BD7DTBI)%60JGGA

I have search for solution for this in forum and found below:

Again, I tried to do the amendment but due to limited knowledge on html coding, I can’t locate how to amend the code in the new custom theme.

Would anyone can offer help and provide clearer guideline on the coding, such as which phrase of the coding need to be replaced with which phrase for the above 2 problems?

You help is much appreciated!

please understand this is not a coding forum. all the needed details were already provided in the topics you have attached. if you do not have the necessary skills to do it yourself, then the best option would be to hire a local programmer to do it for you.