Any place I should make a reservation June/July del Norte/Primitivo

I walked it in July 2019, and did fine without reserving way in advance. There were a few places that were harder to find a bed or room, like Castro Urdiales, Comillas, and Ribadesella. You will get a feel for how busy the Camino is in your first week or so, and will be able to judge whether you need to reserve a day or two ahead or not. I did find that some of the municipal albergues were pretty small, so it was necessary to get there fairly early. For example the municipal albergue in Lezama only has 20 beds, and several people had to sleep on mats on the floor. Many towns only have private albergues. It appears that Zarautz no longer has a municipal albergue, but there are several (more expensive) private options. The albergue in Deba has plenty of beds - 56, but there's not much other accommodation in town, so getting there early is important.