If Lightning Greaves is attached to the only creature you control, you won't be able to attach other Equipment to it (or target it with anything else) until you have another creature onto which you can move Lightning Greaves
Depending on how your local game store handles things, you might have to specifically sign up to attend or just show up on the day, but typically participation sees you purchase a special pre-release pack which will give you a life counter dice, six booster packs from the set, and a special promo card
When running Store Championship events, you also don't need to worry about playoffsif you don't have enough players in your event to cut to Top 8, you may run Swiss rounds and provide prizes based on standings
Theres nothing worse than a common card in your extra deck, alongside all of your shiny Fiendsmith cards
It also only hurts opponents