Buy flats if you value walkability, frequent dabbing, or hate the clipless learning curve. Buy clipless if you want locked-in power and are willing to practice clipping out.
Coming off years of used bikes often means whatever pedals came bolted on. Treat pedals as a real choice. More: cycling and first upgrades.
Two valid philosophies
Flats — Instant bail, cafe walkable with normal shoes (or sticky rubber), excellent for park/jumps and new riders. Demand real pins and a big platform.
Clipless — Efficient connection, consistent foot angle, clearer sprint platform. Demand practice and shoes that match the cleat standard.
What to put on the bike
Related
Install easier with a repair stand. Keep the rest of the bike honest with wear parts.