Normally you need to wait until theres an instant or sorcery on the stack, target it with a copy effect like Reverberate, and then target that spell with another copy effect but now a scheme can fill in for the second copy spell
Otherwise, buying cards standalone is perfectly legit as well, especially for some of the less pricey picks from the latest Universes Beyond set
Disney Lorcana TCG Into the Inklands Gift Set $29.96 A Disney Lorcana Into the Inklands Gift Set includes 4 booster packs
This ambitious issue was designed to improve upon their Unlimited edition, their previous core set, by tweaking the artwork and clarifying the rules text
According to the official MTG tournament rules: "When a judge creates a proxy, it is included in the player's deck and must be denoted as a proxy in a clear and conspicuous manner." But although a proxy made in this way is considered an 'official proxy', you can't turn up to your next tournament using it
