The game is about surrounding territory and every move has got to lead to the best outcome, ultimately, to surrounding more territory than you opponent. The easiest ways to surround territory are described below. Please remember these are to illustrate the topic. No-one would play like this.

All of these stones are surrounding one point of territory:
As you can see:
the task required three stones in the corner, five on the edge and seven in the middle
it is more efficient to start in the corner
an old proverb described the corners as gold, the edges silver and the centre as grass
AI software confirms the validity of the proverb
It is a feature of the fuseki that you can ignore your opponent’s moves. As has happened here (again an illustration):
In this illustration:
Black has secured a corner with 1 point of territory.
White has secured a corner with about 17 points territory (it might not yet be obvious)
Black has played safely but inefficiently
White has secured a corner with maximum efficiency. If White tried to take more territory the corner would not be secure and Black could choose to take some of it.
This could be a real fuseki
This is one example of the many ways a game could begin:
With moves 1-4 the players have started in the corners .
Black move 5 was to share one of White’s corners and moves 6 – 9 was one standard response in which the outcome is considered even (a joseki)
After move 9 it might look like that Black has got slightly more than White in this exchange but White has sente and is free to play elsewhere. This is valuable and balances the account.
On move 6 White could have responded completely differently, for example with another joseki or a counter attack. Joseki is another study topic and the counter-attack is still about fuseki .

Our YouTube channel has a collection of videos specifically about fuseki, it might be worth starting with “fuseki insights 1-8”.

The introductory books listed at the start will help but more specialised studies include:
(1) Opening Theory Made Easy, Hideo Otake, 9P Amazon.
(2)  Fuseki Revolution: How AI Changed Go, Toramaru Shibano, 9P Amazon.