Query results to repeater when the structure is defined from the editor, not coding?

Dear all,
I am trying to learn how to use query instead of filtering, as this would be a more flexible way for me to analyze the results. Again, I am a beginner Velo/java, I read everything I could find but beside the general structure of query to repeater I still have some questions. This is the example code I am basing myself off (sorry it’s a screenshot, but for some reason copy paste in a code section looses all the formatting, this is the link to the useful post I looked at: https://www.wix.com/velo/forum/tips-tutorials-examples/how-to-display-your-database-content-in-a-repeater )

My questions are multiple:

  1. If I defined and connected the repeater structure to the dataset through the editor graphical interface, does it still work? Do I have to start from scratch and define all the items of the repeater in the coding as well? Do I have to define only the ones affected by the query function? Like my database have 10-12 columns, but the repeater display data from only three or four of them.

  2. How do I match the query results to the correct field in the repeater? I cannot find a place where all the items that come out of the query are defined. In other words, if the query gives me 10 results out of a database, those results are associated to 10-12 different columns, where and how that information is stored?
    I guess that for point 2, what I am referring coul be clear from the following code (from velo api). HEre I am running a query and then the console shows me the first results, that has several values associated. I I want to refer to one of those values from all the results of the query, which syntax should I use? For example in the code here, I would like to have the results 1-10 (so I guess results.items[0,9] but retaining only the “_id” value… how do I recognize and see/save those values?

import wixData from 'wix-data';
4		.include("city")
5		.find()
6		.then((results) => {
7			let firstItem = results.items[0]
8			console.log(firstItem);
9		});
12 /*  firstItem is:
13  *
14  *   {
15  *     "_id":            "1d8a1d97-93d3-4d6c-9a0f-c279058b4aa5",
16  *     "_owner":         "81c9168e-95b8-47fd-8e6a-ad9fdf71b38e",
17  *     "_createdDate":   "2020-08-03T10:26:26.825Z",
18  *     "_updatedDate":   "2020-08-03T10:27:01.558Z",
19  *     "first_name":     "Betty",
20  *     "last_name":      "Boop",
21  *     "city": 
22  *            {
23  *              "_id":            "a99daca6-0400-4ef1-8d74-de3f9095bf0b",
24  *              "_owner":         "81c9168e-95b8-47fd-8e6a-ad9fdf71b38e",
25  *              "_createdDate":   "2020-08-03T10:22:39.114Z",
26  *              "_updatedDate":   "2020-08-03T10:23:25.042Z" ,
27  *              "city_name":      "Los Angeles",
28  *              "state":          "California"
29  *       }
30  */

I really hope someone could help me and sorry if the lingo is rough!!