If they have lice you should be able to spot the wee beasties when you part the coat. then spot-on as discussed above should do the trick, sometimes needs repeating as eggs hatch etc etc. Just tell the merchants that you need it for sheep/lambs, some are a bit edgy about selling stuff that is not licensed for goats. Otherwise your vet will have it too.
Check the back of their feet just above the heel and if the skin looks raw and scabby they have got heel (chorioptic) mange. Eprinex will deal with this, but you will need to get it via your vet. Maybe they can get you a single dose, otherwise it's quite expensive.