Runes are more of a Germanic/Norse tradition, not really a Celtic or druidic one. Which futhark have you been given? The elder, younger of Anglo-Saxon? There are variations in number, symbols and interpretation. Most “standard” rune sets tend to be the elder futhark, it’s more difficult to find material on the younger futhark – the futhark that would have been used by Scandinavians during the Viking Age. If they’re Anglo-Saxon, they’ll be slightly different again. There are volumes and volumes of materials that have been published on runelore, as usual, some good, some bad and some indifferent. I’d recommend looking up the ancient rune poems as a place to start – depending on which set of runes you actually have. So, to cut a long story short, look up which set you have and then find the rune poems that correspond to them and take it from there.
Hope that helps.