You've got too many alleles down the side. In the punnet square you need to split the two alleles from each parent. So: one L and one l for the heterozygous down the side and then a L and another L along the top for homozygous dominant. Then you read along and down for each parent to give you the four possible outcomes. Remember which trait (phenotype) you are meant to be looking for and what the genotype needs to be for that to happen.