You have to be more specific than general riding. IMHO a modern mountain bike should simply come with a dropper post, and in general it is a worthwhile investment in money and weight. For the same reason the added weight of a rear suspension pays off, too.
Without a dropper post you either have to manually adjust the height from “uphill” to “downhill/trail” mode or find a compromise that works everywhere somewhat. A saddle at the proper height for climbing will make it much more difficult to shift your weight back especially, and you can quickly go to a compromise setting in a region where you quickly go from seated to out-of-the-saddle. And you first need to spread your thighs to make the ears of the saddle fit through your legs.
I have no idea what you are riding, but I’d definitely keep trying. Watch a few youtube videos. Don’t give up and get out on the trails and ride! 