How to combine multiple values ​​into one value in Google Sheets?

Question

Google Sheets

I want to make something like a table of goods.
A few questions

1. How to do something like auto increment in google spreadsheets (hereinafter GS) ? Google itself offers a simple formula =A1 + 1, that's it, but how can I make sure that when automatically moving to a new line, this value is automatically added?
   
2. How to make a dropdown list with def. values. GS advises me to use data validation and add data to it or select from a range. Everything is fine, but I would like each value to have its own value. For example, the Color column, I can choose colors in the cell from white to black (which I wrote in advance), but I want white to have its own internal id, white = 1, black = 12. I need this for 3 questions.
   
3. How to collect a value from previously filled in values ​​to create a product SKU? For example, I chose the type of product, then the color of the product, and the id of the product has already been created by itself. Further, from these values ​​it should turn out something like this 1-12-001 or how to make it take the first letter from the product type, the first 3 letters from the color, and a few 00s automatically added to the product number. For example, if id = 12, the color is black, the product type is g, then the article should be G-CHER-012
   

Lessons seem to be on youtube, but a sea of ​​​​water, not useful information. Thanks in advance.
PS How to glue values, I kind of know: =A1&"-"&B1&"-"&C1

Answer 1

After sitting for 5 hours, I achieved something.
Namely, I solved question 2 and question 3 (the first part of the question)
Answer for question 2:
Make a column for the drop-down list, put a column with numbers next to it, attach the drop-down list to the cell through data validation, then call the desired value through VLOOKUP.
Added false to the end so that the search is word for word.
Answer for 3 questions:

=VLOOKUP(D2;'Значения'!A$2:B$21;2;FALSE)&"-"&VLOOKUP(G2;'Значения'!E$2:F$29;2)&"-"&IF(IF(A2 >= 100;TRUE;FALSE);A2;IF(A2 >= 10; CONCAT("0";A2);CONCAT("00";A2)))