Drupal 8.x

Hi everyone,
Today i download Drupal 8.3.7 to install for my studying project. And i was find out a problem in our installation function.
Here is report of the error when install in xxamp localhost server:
"Fatal error: Maximum execution time of 30 seconds exceeded"
"in ....\Drupal\Core\Database\Statement.php on line 59"

I have an view which display group by content(basic pages, article and forum). I need to have an create content link.

i.e., if suppose am in article group view, it should have create article link.

i have created an custom block like group operation and placed it in the content.

I can able to see an dropdown like below

Note: Previously i have created an group above operation is also listed in sidebar.

Please anyone help me out.

can i call twig file from javascript file in drupal 8?

i am a beginner but i am using drupal8.3.6, before i was using d8.3.3 and i had built my site almost to finishing it but it started to bring ,"the website encountered an expected error,please try again later.. " everytime i would click on any menu item like extend,appearance, reports and others.
but after i when i upgraded to a new version to drupal 8.3.6 and it stopped. but now it has happened again.and now when i click on " Extend" on the Menu bar it doesnt render it brings " Website encountered an expected error.please try again later"

I cannot upgrade my site beyond 8.3.4 without generating a ["user_role" entity type does not exist error]

I have attached a PNG of the error message.

When I go back to 8.3.4 the site works fine with no error messages on status page (except that Drupal needs to be upgraded to 8.3.7).

I'm running PHP Version 5.5.38 with a memory limit of 134217728.

I have no undefined field names or field types.

I'm logged in as user 1 and have rebuilt permissions and flushed all caches.

I've had no other problems except not being able to upgrade beyond 8.3.4.

Hey guys,

What I try to accomplish is: for each referenced entity add n* fields; to be more specific, I have two entities: ingredients and meal;
for meal, one field is of type "Entity Reference"; this way I can add as many ingredients as I want for my meal;

So far, so good. But now, I need to add two more fields(quantity and description) for each ingredient selected(from a checkbox list of referenced entities)

Is this possible just using some modules?