Yes - when you click "lets go on patrol" - 14days will pass before you get onboard.
Operation Weserübung - is a time restricted objective and you should have been told by radio message well in advance to head to Norway waters and wait for new orders.
Are you using TDWs UI? - Did you get the radio message?
See here from post one about campaign objectives.
Campaign Progress
Within each campiagn (i.e. coastal Waters) there are main objectives to achieve. These will be things like "sink 50,000 tonnes of coastal shipping". As you achieve this tonnage a progress bar will fill so you can keep track of your progress. When the bar is full, you have achieved the objective and will be awarded crosses to fill your campaign bar.
Most of these objectives a time/date related and if you fail to fill the progress bar within that time - you will fail the objective.
Failing the objective will not stop your campaign. You may have some blocked objectives or even blocked campaigns as a result, but your career will continue.
If you finish an objective within the time frame given - you may not get a new one untill a later date. When this happens, you should go out and patrol anywhere you like, hunting any ship you like. this is a good time to test your skills by trying some harbour raids etc.
When the time comes for a new objective, you will be sent a radio message informing you that new objectives are ready. You do not need to return to port and select it. You can just go and start the new objective from where you are. You DO NOT EVER need to select an objective from the main briefing map.
When you do select an objective from the main briefing map, you will also be given a secondary mission. This will be thing like "Drop of supplies at area X"
see here for an example When you achieve these secondary missions, you will be rewarded with extra renown points that you can use to upgrade your u-boat. If you do not do these secondary missions - there is no penalty.