Simplest IP lookup API for noobs?

hey everyone, i just launched my little saas a few weeks back and i'm realizing pretty quickly how much i need some basic location-based personalization. things like showing local currency, or region-specific content, would really make a difference for user experience.

problem is, i'm a total noob when it comes to geolocation stuff. trying to figure out an IP lookup API has been a bit much; there are so many options out there, kinda paralyzing for someone just starting out.

• what's the absolute simplest, most beginner-friendly IP lookup API you guys would reccommend? ideally free or super cheap to get started, budget's tight post-launch.
• are there any specific tools or libraries that make integrating this stuff really straighforward, especially since i'm running a Node.js backend? anything that plays nice with that would be a lifesaver.
• also, what are some common pitfalls or big no-nos a total newbie like me should watch out for when trying to get location data? don't wanna make any dumb mistakes.

help a brother out please...