As the title says I need advice, help, recommendations for a all puzzle dungeon for a group of new but smart players. They been through a number of different combat encounters and I want to give them something different to deal with. I was hoping to set up a "Never-Ending" temple similar to the one in Steven Universe where the rooms seem to go on forever but theres a secret room that holds the actual exit/key to the exit.

Here is my advice:

When doing puzzles, there is going to be an obvious gap between what the players know and can see, versus what the characters know and can see. You'll have to make sure descriptions are robust enough that the players can have a really good grasp of what is going on in the room, so that they don't miss pretty obvious things because they forgot you said there was a crate in the corner when their character could obviously see the crate. Also, someone might be playing a very intelligent, private investigator-type character who would be great at solving puzzles in-game, however the player might not be puzzle oriented. Consider allowing certain skill-checks for hints to the puzzles, because characters might be better at figuring things out than the players.

Also, if the players start getting frustrated and seem to be losing interest because they just can't seem to figure out the next step, drop a hint or progress the puzzle in some way. It isn't fun for players to sit around just trying to think of a 10th solution to the puzzle when their first 9 have failed and they are out of ideas.

There are a lot of great resources for different puzzles online, but one thing I like to do is create a puzzle with no "true" solution. One example of a "puzzle" my characters encountered was, while trekking through a mountain cavern system, their tunnel ended on to a deep cavern with stone pillars, stalactites, and magma flowing everywhere below. They needed to figure out how to cross. There's no "correct" solution to this puzzle, but when they make a good attempt, reward that! Not everything will work, but if something can reasonably succeed, let it! My players had a staff that gave one person Spider Climb, and they used it to hoist a rope to the ceiling, allowing them ,with a successful Strength roll, to swing the other members of the party across the magma river to the other side. They could have tried other things, such as using their Endless Water jug to try to cool enough magma to walk across, they could have tried to topple one of the stone pillars to make a bridge, or bring down stalactites to do something similar, etc. Sometimes not have a "true" solution allows the players more freedom in figuring out solutions.

See if you can get a copy of this book:

The game master's book of traps, puzzles and dungeons - Jeff Ashworth

1) Even if the entire dungeon is just a series of puzzles, make sure to still sprinkle some combat in there too so the players who aren't engaged with the puzzles can feel useful too. You can combine the two -- i.e. there's a seemingly endless number of (monster) pouring into the room, and the barbarian and paladin can keep busy smashing them to buy time for the wizard and bard to figure out which lever(s) to pull to seal the door and stop them from pouring in

2) Make sure there's a mix of mental and physical challenges to solve, and different skills that can/will get used

3) You could consider making the entire dungeon one big puzzle containing a bunch of smaller puzzles -- i.e. every room contains a puzzle, but the party will still get through even if they don't solve it, by brute force or whatever. How many of those puzzles they solve, however, will determine how easy the final Boss Puzzle is/how many clues they acquired along the way

Thank you for the help! I think I've got what I needed worked out.