The first, second and third condition in French

[Crack1]

If I have money I will buy a new car.
If I had money I would buy a new car.
If I had had money, I would have bought a new car.

Si j'ai de l'argent, j'achèterai une nouvelle voiture.
Si j'avais de l'argent, j'achèterais une nouvelle voiture.
Si j'avais eu de l'argent, j'aurais acheté une nouvelle voiture.

Are all my French sentences fine?

[George Hunt]

I think they are all good .

There may be other ways of expressing these ideas.

For example I think  "Si j'aurai de l'argent, j'achèterai une nouvelle voiture." may be possible.

But I am not confident about this.

[Chantal Savignat]

Si j'aurai : non.

we have an expression to remember that, because it's a very common mistake and a lot of french native do this mistake.

Les "si" n'aiment pas les "rais" : sentence that sounds in french exactly like "les scies n'aiment pas les raies" (with a play on words "scies" and "raies" = fishes). 

which means : with "si" it's totaly impossible to have the verb  in "rai" or "rais" (understand : the conditionnal, not the future).

There is a  marvelous ans charming movie, very know, in France : la guerre des boutons (movie about chilhood). One of the children, Petit Gibus always says "si j'aurais su, j'aurais pas venu" with 2 big mistakes so cute in the mouth of this little boy.

[Crack1]

Thanks Chantal

To say 'do mistake' is sounds  odd.

It is 'make mistake' .

[Chantal Savignat]

thanks Crack1.