Natural Resists
Natural enemies
Before going into ship types you need to know the races, and more importantly who are enemies to each other in order to understand how the natural resists work.
Amarr VS Minmatar
Gallente VS Caldari
Each race has a dominant dmg type
Amarr
Amarr deal both EM and explosive, but does more EM damage throughout all ammo types. This makes EM the dominant Amarr Damage type
Minmatar
Minmatar deal all damage types depending on ammo, but 6 out of the 8 ammo types you will find some explosive damage. Most people will argue that projectile ammo can be interchanged to deal any damage type, however for the sake of this topic; we will stick to Explosive as the Minmatar dominant damage type.
Gallente
Gallente deal high kinetic and thermal
Caldari
Caldari missiles have the versatility to deal all damage types equally well. However, three of their most popular ships also have bonuses to kinetic damage. So it is safe to say that Caldari have kinetic as the dominant damage type.
Tech 1 Ships
Generally all Tech 1 ships (and faction ship) follow a general pattern when it comes to resists. For a given race, all tech 1 ships and faction ships have the same resists, be it a tech 1 frigate or a titan. A Punisher has the same exact resistance attributes as an Avatar.
All tech 1 ships have an EM shield hole and an explosive armor hole.
However, resists between different races vary slightly, main to compensate for the dominating enemy race damage type.
lets take a look at the different tech 1 ship resists by comparing the natural enemies.
Amarr VS Minmatar
As you can see, the Minmatar tech 1 ships have a slightly higher EM armor resist to compensate for the dominant Amarr damage type. Likewise, the Amarr tech 1 ships have a slightly increased explosive resist to compensate for the dominant Minmatar damage type.
Gallente VS Caldari