Not sure how to call features i want to add?

I am just starting out , and i just dont know the words for the features im looking for , and how to reach out to them .

So i’d like to know how to call them and also if you know any that match my description:
(there are some technical thing in the end)
this is my demo site https://www.shitnootropics.com/

Home page : ATM its just menu at top and most recent posts-
Menu
>
Id like that beneath the menu would be a Carousel? of the latest posts
But a nice small one that would show maximum of 3 at a time .
>
beneath that , Just Box shaped pictures each redirecting to different category (with the category name mentioned somewhere on theme or when hovering) and graphically interact when you hover on them and not static.

>
the recent posts.

on posts , id like to add at the footer? a slim thin carousel for the most trending posts.

couple of things im not sure i can adjust with my current theme, and want to know how:

*the pictures of the recent posts are just huge , and it takes alot of space in the homepage , how can i customize picture size within wordpress?

*the sample text of each recent post on the home page is too long and i’d like to adjust it too much shorter value.

*when entering and actual post , the thumbnail picture is just huuuuuuge , and alot of times it would just look bad because of resolution –
https://shitnootropics.com/a-test-for-you-fuckers/

can i edit it?

Posts dont have a menue on the page , only the homes page, Can i change this somehow?

If you happen to know the answer to any of these , i would appreciate it.

(is there design forum here?)