La-Qa,
Please understand that we are not here to do your work. We are here to explain you and help you grow in your field of expertise.
As a SDM administrator, SQL knowledge is mandatory. Accessing custom fields in related table is propably the most simplest SQL operation. You NEED to take a SQL course like this one : https://www.udemy.com/microsoft-sql-for-beginners/
Getting your related tables information will be done exactly like James showed you for ca_contact, chgcat, chgstat, pri, impact etc...
Please take 1 hour to understand what he did and apply it to your custom fields. This way, you will be able to do it all by yourself next time.
So in the end, what James gave you is highly sufficient to achieve what you want without further help.
We will gladly review some SQL notion with you if you need to but we will not type the query for you.
As a conclusion : Give a man a fish and you feed him for a day. Teach a man to fish and you feed him for a lifetime