Neodymium magnets are so powerful that you should watch this before buying one. I give guidelines for size, shape, grade and coating. In this way you hopefully will have a good start with a nice beginner magnet.

Lin to video with the Macho Set: https://youtu.be/Dh1S9kgz6aw

Link to detailed safety sheet:
https://www.supermagnete.de/eng/safety.pdf

Link to shown sample sets (European shipping only):
https://sumag.net/mag-sets-x01

I have no personal experiences with magnet webshops outside Europe. For US/Canada it seems that http://www.magnet4less.com has the best selection at very fair prices. I haven't found any sample sets in their webshop though.

Another cheap source for neo magnets are scrapped hard disk drives. It can be tricky to open the drives though and the magnets are specialized. Here's my video about them: https://youtu.be/ep_VCotA1ZY

Full music credit:
Kevin MacLeod from http://www.incompetech.com
Tracks used:
Tempting Secrets (ISRC: USUAN1300038)
Decisions (ISRC: USUAN1100756)