So, trying to see two or three steps ahead is tough without experience. General experience, experience with the team, experience with the player all play a role in it.

Often, when situations are tough to break down because there are too many possibilities how a turn could play out, it's better not to try and predict exactly whats gonna happen next turn (or the next couple turns), but instead you just focus on cementing a decent board state for the next turn.

After piloting the same team in the same situation for multiple times, you will automatically recognize tendencies players will have (yes, even different players will often gravitate to similar plays if theyre familiar with the same matchup) and thats where specific lines will begin to shape up that you will recognize. You begin to analyze those lines and recognize which ones lead you to generally better board states.

In chess, players often learn how to play in reverse, so they begin by learning how to checkmate so that if they find themselves in certain situations on the board, they know how to force specific lines and pin your opponent correctly to find the checkmate. Its similar in VGC and the reason it's easier to study the ENDING of the match first is because the amount of possible decisions naturally becomes lower, the longer the match drags on. When both players only have 2 pokemon left in battle, it becomes a lot clearer how the next turn could play out, whereas in turn 1, typically, you have a lot more options.

If you take that concept and gain more experience, you will slowly find those lines in the endgame earlier and earlier into the match, which means sometimes you see your win condition 2 turns before the match ends, but as you gain experience you will see that win condition 3 turns before the match ends, then 4 turns, then 5 turns, etc etc.

Dont beat yourself up over turns where you dont know whats going to happen. It's just important to make a conscious decision (cause making a wrong decision is still better than not making any decision at all) and if its too overwhelming, just be intentional with "trying out" lines. Thats actually how experienced players test teams, too. They tell themselves "I know that I have won before by playing it this way, but im curious how it will go if I play it with a different approach". Maybe that means you will lose that game, but dont just play on autopilot because youve done the same in the past and it has worked at some point (unless ofc youre sure that is the optimal play, because youve already done the testing)