First Conditional

The first conditional is used to talk about real or possible situations in the present or future, often to express cause and effect. Here's the structure:

If + present simple, will + action verb

For example:

If we do the check-in on time, we will fly to Manchester Airport.
If she saves money, she will go to London.
If you don`t have a more than 6 months valid e-passport, you will not be able to check-in.
If they stay more than six months, they will have to apply to e-visa.
If we don`t buy seats, we will not sit together.
If he rents a car, he will not need to buy train or bus tickets.
If she doesn`t book the hotel now, she will pay high price.
If you don`t buy home when young adult, you will not afford to pay the rent when you become elderly.

It implies that the condition ("if...") has a realistic chance of happening, and the result ("will...") depends on it.