Choose a Pokemon that’s in front of you. Toss two coins – for each that comes up heads, remove two damage counters from that Pokemon.

Kanji used:
あなたの場 = あなたのば = “your place”, which I’ve elected to translate as “in front of you”
一匹 = いっぴき = “one animal” – 匹 (ひき) is the counter for small animals
選ぶ = えらぶ = “choose”
２枚 = にまい = “two [coins]” – 枚 is the counter for flat things
投げ= 投げ = “throw” – this is the written equivalent of the て-form
「おもて」の数 = 「おもて」のすう = “number of ‘heads’ ”

Suggest you find yourself a good kanji dictionary – it’ll let you look things up. I’ve got imiwa? on my iPhone and iPad, though I’ve also got Spahn and Hadamitzky’s Learner’s Kanji Dictionary (it’s the slightly slimmer version, which has only the Joyo kanji).