Discuss and learn French: French vocabulary, French grammar, French culture etc.
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.
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.
To say 'do mistake' is sounds odd.
It is 'make mistake' .