First press versions of singles are, as their name implies, the versions you'll get if you buy the singles on their release date or quickly after. You usually want to preorder them if you're not living in Japan.
Each first press version of a single comes bundled with one photo. And as singles are sold in four types (three before Fukyouwaon), there are 4 different photos for each member that are split up like so:
Those are photocards either only available during Keyakizaka46 events or on the online shop. There is often an overlap between those sets, which is why they are grouped into the same category. Whether it is at the venue or online, they are however sold the same way: you have to buy a set of 5 random photos for the Kanji members or a set of 3 random photos for the Hiragana members. Not unlike the first press photos, three types exist for each members: yori (ヨリ), chuu (チュウ), and hiki (ヒキ).
This type of photos, that are mostly only obtainable on the 2nd hand market for foreigners, is perfect for those who want photos of their idols dressed in their MV or live outfits which aren't bundled with the CDs.
The other types of photosets that exist include magazine photos or Sengen (欅宣言) photos. Sengen (announcement) photos were the first photosets that were sold when the group had just debuted and are hard to obtain as of now.