No judgement, we all start somewhere!
With the plastic sleeve, as long as it is less than 1/4" thick, I can get a 70 cent stamp at the counter and ask them to hand cancel the card. They usually do it on the card, then I slip it in the envelope and seal it, then they stamp it on the outside with something too. This time, the leafy didn't stamp at all, but put it in the special processing pile. I hope it doesn't have issues getting to you!