Welcome to the Forum and camino.
Easter week is busy because lots of spaniards walk for the weekend, or whole week at Easter.
It isn't impossibly busy... You can find space in an albergue every night, but it could be crowded.
If you like people and are laid back, Easter week can be a lot of fun because some pilgrims like to party.
I recommend starting in Saint Jean Pied du Port. You can take the transit bus or a taxi to Bayonne train station, and then the Train to SJPP.
You will be able to walk to Viana or Logrono in 7 days. You will pass some special places and nice towns along the way. Pamplona, Eunate, Puente la Reina, Estella...
The first day walking out of SJPP is challenging because you walk through a mountain pass to Roncesvalles. Pilgrims talk about their experience on this first day all the way to Santiago. There are two routes from SJPP to Roncesvalles. The Napoleon route is beautiful, but can be dangerous if its snowing or foggy. Listen to the people in SJPP's advice about walking it that day. The other route mostly follows the road, and has the town of Valcarlos about half way. It is a good alternative if the conditions are less than ideal.
Pour through the many discussions on this forum. They will inform you, excite you, and prepare you for a good experience.