Modifiers will become interesting to you after you finish the main story and get a decent legendary gun. Around this time, you will have enough of them in your inventory to have plenty to choose from. And here you can learn about nightfall weapon rotation https://wowvendor.com/en-us/portal/destiny-2-nightfall-rewards-this-week/ . Nightfalls are one of the activities that reward Pinnacle gear, essential for raising your Guardian's power level beyond the soft cap, crucial for endgame content.