In the first conditional both the if-clause and the main clause are in the future tense. The present simple tense is used in the if-clause, and the future simple tense used in the main clause.
Don’t use will in the if-clause.
If the weather will be good, we can go for a walk.
- If the weather is good, we can go for a walk.
If I will see Gary later, I’ll give him your message.
- If I see Gary later, I’ll give him your message.