两 (traditional 兩) pictured a paired yoke or a balance with twin pans — two things built to go together. It was also a weight unit (the tael, 一两银子 of every period drama).
Chinese has two twos, and 两 is the one you actually use before things: 两个人 (two people), 两点 (two o'clock), 两百 (two hundred) — while 二 stays for counting and math. Getting 二/两 right is a beginner milestone (两个, never 二个). Bonus meanings: 两 is still the tael (50g) at tea shops and gold counters, and 我们两个 ('the two of us') is friendship's smallest unit.
A yoke built for a pair — TWO of something.
二个 is the error every learner makes exactly once out loud. It's 两个 — the correction is a rite of passage.