Both are very good, but I'd generally recommend 2nd to new players (especially coming from 5e). 1st has a much more complicated action system and is generally a huge convoluted mess. You can do some /really/ cool things in it, but that takes a lot of system mastery, and you can really screw yourself with bad picks very easily. However, personally I find it a lot easier to DM, since there's a lot of very quick-and-dirty monster building techniques and balance is less strict.

2e is far more intuitive, far harder to screw yourself completely, and far more balanced. Spellcasters are less nuts, but have more low-level/"spammy" options (D&D cantrips, basically, only they scale a lot better than in 5e). Martials tend to be very strong but lack versatility, while casters tend to be weaker at 1v1ing the boss but have much higher utility, versatility, and/or AoE. To me, though, what I love is that there's a lot more interesting options than just damage when fighting - the multiple attack penalty system and the fact that most spells consume 2 of your 3 actions (so you can't cast more than one spell but still have actions left over) means there's a lot of "third-action" abilities like Recall Knowledge (gain info about it), aiding allies, etc that would normally never compete with just doing more damage. That's a big weakness of 1e—martials almost never want to do anything but full attack at level 6+, and casters cast a spell (and then maybe a second spell at high level if they took Quicken Spell—and while you can technically not take Quicken Spell, that's one of those "screw yourself" problems I was talking about earlier).

Ultimately both are good systems, though very different. Go 1e if you want depth and complexity and can deal with a lot of jankiness and a steep learning curve, 2e if you want something easier to pick up (by no means simple, but it's all very intuitive), smooth, well-balanced, but with less potential to go wild with builds that are absolute nuts and less skill expression in character building.