A temperature/humidity monitor, an NFC tag automation, a macro pad, a basic LED project, or a Meshtastic node (on sale). ESP32 boards start around $5, and useful sensors cost $2 to $8 each. Small budget, real projects.

Yes, for learning and prototyping. A $5 ESP32-C3 has Wi-Fi, Bluetooth, and enough GPIO for most starter projects. You lose some polish (no built-in display, minimal documentation), but the silicon is identical to pricier dev kits.