1 Player hardcore
3. This is how you pick missions. You draw the number of target cards your entitled to. Let's say you draw three cards. From these 3 target cards, you select a Primary mission. Of the remaining 2 cards, you may select a second target if either has the Secondary trait. You then select pilots for each of the two missions. Note, individual pilots can only fly one mission per day. You then complete the first mission, then you complete your Secondary mission.
Also keep in mind that you only draw Target cards one at a time. You are not required to draw your maximum allowable amount of cards at once, nor can I think of any reason why you'd want to. You also don't have to draw any cards. This is useful if you plan on attacking & ridding yourself of Targets with an "improvement" trait and don't want to risk drawing any more. Having a backlog of Targets with the "improvement" trait can really hinder your campaign. You may also want to rest your squadron for a day, in which case there is no reason to draw any Target cards.
From page 7, in the lower left column under Recon (Reconnaissance):
This rating sets the upper limit on the number of cards you may draw. You may chose to draw each card one at a time.
Example: If you already have several Improvement Target cards lingering from previous missions, you may not want to draw more Target cards and risk bringing more Improvement Target cards into play.