Do you need to revise solely first conditional clause's form and meaning? Here's a sentence making worksheet with an answer key on only type 1 if clauses. It covers exclusively type 1 if clauses to revise both form and consolidate the meaning behind it.
In the worksheet, there are some situations given in each exercise. Students need to make sentences with first type conditionals to match the condition described in the case. You should be ready for various answers as each situation can be described with different first conditional sentences. Nevertheless, the context should be the same in all answers. You can ask for a class opinion on different answers which will be a great consolidation activity as well.