Choosing a JS stack for a personal account - where to stop?

Question

JavaScript

Good afternoon!
Unfortunately, I lost my old account, and I don’t know my mail, I had to create a new one. :(
Please tell me one thing, I have a little doubt about the methods for solving the problem.
I am in the process of learning JS, in addition to solving problems for sorting, recursion, etc., I decided to try to do something more or less similar to a project, to master not only solving problems, but also something real for stuffing bumps.There
is a desire to make a simple CRM, a task scheduler, it doesn’t matter.The internal functionality is not important, the basics of authorization and the frameworks used are more important.So
, what tasks I would like to set and solve for myself:
1 ) Authorization form, with the possibility of registration;
2) The simplest tabular display of data, conditionally:
[Company 1] -> Call/write an email -> [comment field after the action] -> button with date/time selection for the next action
3) Possibility of further assembling what has been written into a desktop/mobile application
Everything, nothing else. I just want to understand in detail the creation of authorization and port on desktop / mobile.
So, what is the best use for this in 2019?
I must say right away what I DO NOT want and DO NOT know: php and all its derivatives, any CMS.
I really want to do without jQuery.
Conditionally, I just ask you to suggest the technologies that are better to use. What DB is better to use? What is better (in my case === safer) to accept login data and process it? Which zoo of frameworks to use?
The amount of time is Infinity. I do all this after work (which is not related to IT at all), just for myself, because. interesting. I ask the question because there is a lot of conflicting information, for example - don't use ajax, it's bad. Is that so? And why?
Ideally, it would be better to understand what would be more promising from the stack for further study of the issue, adding functionality, etc.
Thanks in advance to everyone for the replies. If I asked something stupid - please do not call me a fool, but simply ask to be corrected. :)
Thanks!

Answer 1

There is a desire to make the simplest CRM

Make a simple ToDo List/WeatherApp first.
Any. MongoDB or MySQL for your eyes.
Any modern framework.