Once you "complete" the tutorial you have full control over what you want to do, no pestering side tutorials or anything that will stop you from enjoying the parts you want. Well, that is if you are loaded. The paywall behind the energy system will hit you very fast and hard at about 10 minutes of gameplay. That is if you just play for the game and are not jerking off to the hot pics ;)
The story mode is super easy to play as in "click the next button" simple. Each "next" press will cost energy and award you exp that will eventually make you level up. Level does nothing except raise your energy pool. So yeah no strategy is involved here since leveling up only gives you 10 energy unlike other games like this where leveling up refills your entire energy pool. Just click next without thinking too much and either wait and come back refreshed or pay up to replenish your energy.
As I mentioned in the review you can recruit units through the gacha system or the story, once you unlock them you level them up by using items that you also get in the gacha store. The "leveling" is made in the "my harem" menu where you'll see various information about the girls in your harem. Their stats, weapon, type, experience, affection levels, etc... some information does nothing for the actual gameplay but does affect weekly bonuses like their hair/eye color, their astrological sign, and whatnot.
Finally, there is pvp, the only strategic element here is team building. The weapon triangle and the elements are key to winning against a team with the same overall power as yours. Overall power is the sum of your unit's power and level. If you don't care about those systems you just need a team with a lot of overall power. The higher the number the stronger your team is, basically you just need a "stat stick" and you are set.
All of this aside (and it's a lot) there is nothing important for you to know to play the game. There is a customization menu for your avatar and its picture but that's it. Porn star harem is enjoyable and entertaining. The very nature of the game makes it so you'll never "finish" the game. You could gather all the units yes but what about leveling them up to max level? And then you have the ranking in pvp. There will always be someone stronger than you in porn star harem. You'll always have to progress which ultimately is a good thing for a game. Give it a try it's worth it.
You can play Pornstar Harem right here
Enjoy and remember to check out my review of Pornstar Harem.