Translation:When I was young, I would go to Prague every week.
Used to should be ok... Grammar about would: http://www.helpforenglish.cz/article/2010080902-would-pro-opakovane-deje-v-minulosti
Just to a native speaker ear, "would go every week" and "went every week" sound about the same, though as the link suggests using "would" for repeated actions in the past is common. The Czech obviously is not in conditional, which should be would/could/should in English. There must be a specific grammar rule in English but we don't really learn grammar formally anymore.