Drupal 8.x

have been sitting before Christmas trying to figure out how to upgrade the page from D 8.9.11 to 9.1.0. but have not come any particular ways with project. have also tried me to follow "Upgrading from Drupal 8 to Drupal 9 (or higher)" without getting any way with it.

until now I have only used FTP for upgrading so that is why I ask what I am doing wrong with the commands to upgrade drupal

here an error message I get

I'm currently trying to integrate my website into another set of non-PHP back-end code.  I want to use the drupal authentication process, and then trigger certain external activities based on the logged in user.

I had this working under D7 as follows:

1. Get the cookie name - namely, 

strCookieName = "SESS" & Left(sha256(strCookieDomain),32)

2. Read the cookie value

3. Go to the MySQL database, and get the username that cookie belongs to:

I have two vocabularies in my site: categories and tags. When I display nodes, the HTML for the display for categories is different from tags. I want them to be the same look.

Categories is like this:

<div class="field__label">Categories</div>

<div class="field__items">
              <div class="field__item"><a href="/drupal8/web/categories/handouts" hreflang="en">Handouts</a></div>
              </div>

Tags shows as h3 though. 

I migrated over a site from D7 and found that many nodes display whitespace incorrectly. It is running together paras instead of spacing well.

I found that if I open and save the nodes (without changing anything) then the whitespace shows correct.

So I tried to write a small php loop and run with devel/php to re-save the nodes, after changing the node title to change "something" to make the save work. Save works, but the formatting is still not updating when I save. (Site GUI View pane is still wrong.)

Drupal 8 or 9

Can someone give any suggestions on the following:

Let's say I have a festival site, where there are performers, organizers, hosts, and an award given out every year.

I also want to keep an archive of each year (who were the performers, organizers, hosts, and who was the award winner and finalists for each year).

What is the best way to group that together, so that I can create views that would show the artists for a particular year or years (via filtering), as well as organizers, hosts, etc...

I am working on a drupal 8 site. two days back when our seo team run Semrush audit report tool it sudden create a huge list of url by saying duplicate meta title etc what i found in this report its mainly node/xxx pages are sudden start appearing in that list ? how it can be sudden appearing ? No module i installed no code changes. If i wana hide then what should i have to do.