fields in the product info page

I need to display in the product info page (front end) some "input text" to allow the customer to freely write a generic alphanumericstring (i.e.: a dimension in cm.) and, also, to allow to upload a file, to be attached to the eventual order of the product.
I tried with options/characteristics, but I was not able to do that.

In order to do that, you will have to create custom fields of the table "item" (Business edition) via the menu Display->Custom fields.

I tried by the demo site.
I set a custom field (name: marca) with the following characteristics: in the product table, filed type: text, mandatory, Front-end: YES, Category: men

I would expect to find it in the product info table in the front-end, for the products of the sub-category "men", but I did not find anything

I did something wrong ?

PS I have not yet cancelled the "marca" custom field in the demo site. I cancelled it after your answer.

Thanks

Please reread my previous message. I talked about creating a custom field of the table "item", not "product". The custom product fields display the field in the edition page of the product so that you can add additional information to the product.

The demo website is reset automatically every hour.

Ok. I did it succesfully in the demo site.
Thank for the support.
I will proceed with the business edition