As you don't have much experience with baking, I would recommend that you find a recipe for a crust specifically intended for an ice cream pie, and then work from there.
It's possible that you'll find that there's something wrong with your technique, and the crust isn't any better than what you've made so far, but I suspect that your problem is that most pie crusts aren't meant to be served nearly frozen.
Starches and fats can change significantly when chilled. Consider something like long grain white rice -- it may have been perfectly fluffy when cooked, but when cooled to refrigerator temperatures the starches form a hard crystalline structure. Many breads get chewy after they've been frozen and thawed. I suspect that this is your problem with hard and/or chewy crusts.
Our perception of tastes change with temperature as well, so it's possible that you'll need more salt, sugar, or spices in the crust.
I'm not an experienced baker myself enough to know what changes need to be made for ice cream pies, and that's why I don't think that you just need to "focus on making a good pie crust", as even the best pie crust for a fruit pie might make a horrible crust for an ice cream pie. I suspect that there's a reason that many freezer pies use cookie crumb crusts, and not a pastry crust.