Explications:

The first conditional in English is formed with the present simple after “if”

Conditional tenses are used to speculate about what could happen, what might have happened, and what we wish would happen. In English, most sentences using the conditional contain the word if. In all cases, these sentences are made up of an if clause and a main clause.

The second conditional uses the past simple after if, then 'would' and the infinitive: if + past simple, ...would + infinitive.

Second conditional is used in situations/actions in the present or future which are not likely to happen or are imaginary, hypothetical or impossible. If I won the lottery, I would travel around the world and buy a castle

To make a sentence in the third conditional, we use, If + past perfect, would/wouldn't have + past participle. If you had told me about the meeting, I would have come. If you had told me about the meeting, I wouldn't have missed it

First conditional is used to talk about actions/events in the future which are likely to happen or have a real possibility of happening. If it rains tomorrow, I'll stay at home. If my father doesn't buy me a bike for my birthday, I will be very unhappy