I you want to make a Swedish main page, you should contact me: bm at cage dot ugent dot be or user talk page of bmcage
You should be committed to regularly check if updates to the english page appeared you should translate You should also check if other users adding swedish content are not spamming, and if not, quickly check their work.
Next, read the page GRAMPS:Language_policy It lists what should be done. Eg, for the main page, you translate stuff with the help of: GRAMPS:Main_page_templates. Not so difficult after all :-)
If still interested, send me the ISO code of Swedish language, and I make Swedish appear on these page so you can start translating