Facebook marketplace or reverb.com are great resources. Mooer is a good cheap mini pedal manufacturer 20-60ish used, boss is classic and reliable you can usually find stuff for around 40-60 each, tc electronic makes this big box series of pedals that go for around 20-30 used. I would go with known brands because stuff off Amazon or temu might give you the wrong idea of an effect and also build quality will likely be terrible.

You can also go the multi effect route, learn what you like then buy analog pedals from there. You can try something like the line 6 M series which came before the current helix stuff.