I think as a beginner, you'll probably have more fun on a softer ski. Softer skis are more forgiving, and are much easier to learn new tricks like butters and presses on. Stiffer skis are going to be more stable at speed and hold up better on large jumps, which you won't be hitting as a beginner anyway. Stiff skis generally generate a larger pop, but you have to be able/heavy enough to fully load up the tails to do that, which you'll have to learn to do. Softer skis don't pop quite as hard, but are easier to "ollie" because you can more effectively throw your weight off your tails. To ollie on skis, you essentially jump but throw your weight backward to put a lot of weight on your tails and flex them. When you pop your jump, the tails will act like a spring to give you a bit of extra boost, but it's obviously a lot easier to flex a softer ski. You'll need to be able to ollie or pop off your skis before you can learn to hit higher rails, like urban style down rails. Learning to effectively pop also helps a lot on jumps and gives you a bit more air time for learning new tricks. Some good soft park skis are listed below:
-Atomic Punx
-Armada T-Hall
-Line Mastermind
-Line Invader/Elizabeth/Anthem (these skis are discontinued so you'll have to find them used, or search hard online. Some retailers still carry the elizabeth and the anthem, I haven't seen any new invaders in a long time. Elizabeths are also wider, and will be harder to learn tech rail tricks on, but are super fun and buttery)
-K2 Domain
-K2 Press
-Moment Jib
-Others
If you're looking at getting a softer park ski, I would stay away from Salomon, Volkl, and Rossignol. Almost all of their park skis are quite stiff and will be super stable, but not quite as playful. Also, just do some research and use the searchbar. You'll find a lot of good options just from reading older threads made by other people.
