Hola Pirani,

The noun vez is feminine - La vez / una vez, therefore you have to use alguna vez [at some time / on an occasion, ever] or algunas veces [sometimes - plural]. Algunos would be used with a masculine noun, for example "algunos coches."

Here is a great lesson for you to have a bit of fun with. Have a close look at the yellow "Tip" box because there is a very useful instruction in it.

Saludos. John

Using algún (a, as, os) to say some or any in Spanish

Also the word algun@s is interesting because it changes its English meaning depending how we use it.  We see this in the lesson that John linked, but here is a summary, because it took me a while to figure this out.

ALGUN@S NOUNS:  means "some of the noun".  Ex: "algunas veces" = sometimes, "algunos lugares" = some places

ALGUN@ IN A QUESTION: means "any".  Ex: "Tienes algún problema" = do you have any problems, "Hay alguna pregunta" = are there any questions

ALGUN@ NOUN: means "some random".  See the examples in the lesson.

Cheers.