Here let me explain this one as short as I can, you can decide. Pokemon came out when I was in my late 1st or starting 2nd year of college, and before that I had been watching that cartoon you're aware of on TV in the morning before leaving during breakfast so I knew the material so I was curious. The game itself is an interesting beast that has and hasn't evolved in various ways in 20 years now.
The basics of it is this. You're a kid (boy/girl) oddly set out homeless on your own on your quest to be a pokemon master around age 10-13~ish. I know, child abandonment great eh? You're given a starter pokemon of a fire, water or grass type. Think of any traditional RPG where you have various elements and subelements (fire, water, grass, ground, flying, fighting, ghost, electric, steel, fairy, psychic, etc.) Each pokemon can have one or two types along that and each in a pinwheel of death basically have strengths and weaknesses. Water can jack up x2 damage fire, and fire can torch grass, but reversed you'd never take those types backwards or you get your ass handed to you. The rest either do standard damage or with a ghost anything physical hits nothing.
You go around, catch them (all?) 151 in the original batch. Many are easy, some are a bitch to score, a few are a bitch and just hard to locate being 'legendary' which needs requirements. Some games have some the others dont so they'd make you buy both or have a buddy with one, or a pro action replay to cheat unlock the critters. The painful part of the game of which I've only finished 2 of them is leveling up. It's not RPG normal, each one goes up alone. If you need to raise a weakling, you basically have to put the pussy out first, pull them back, let the enemy get a free kick to the teeth on your replacement, and beat down the enemy traditionally speaking. As time went along Nintendo started adding ways to experience share. The very latest of the out X/Y those have EXP share modules, you flip them on, as long as a pokemon is in a ball in your pocket, they all get the XP (very handy, more 'party based rpg' style that way.) The concept is you go around the continent, battle to get better, evolve your pokemon to better beefier evolutions, then kick the crap out of 8 gym leaders to get their badges (tokens of your power/smarts) then take on the final bosses at the end to be the best in the land.
That's really it, they re-do the games every couple of years. It's damned addictive if you commit some time and want to go for it, monumentally so if you're into online/local combat with people, or you have a hoarders instinct to collect things. If not you can easily cherry pick a few of them all and be fine-- say like Yellow, Crystal, FireRed, and X or Y currently. Yellow apes the cartoon and is a definitive version of the first 2 red and blue with tweaks. Crystal is the same but for silver and gold as that was generation 2. FireRed (and LeafGreen) they modernized the origianls so they don't feel dated and they work great and on GBA. X&Y is the newest, has that easy leveling perk, but more of the same but they do add stuff like team battles or 2on2 type fights.
EDIT: My advice to you, try it, but I would only suggest FIRERED for Gameboy Advance. Why? It blends the mechanics of the first 3 generations of the series so it gets you up to speed. You only have to worry about the original popular pokemon (that the Go mobile game is based upon), and it has no battery -- a storage chip for saves so you won't lose it. The old games are notorious for failing due to dead batteries, specially gen2 due to a real time clock. In the last 2 weeks I've had to replace 4 GB batteries over that on stuff I picked up local (Crystal, Yellow, Silver, and Gold) at garage sales.
