You are planning to walk from SJPP in March, right? I think you will find that timing and route to be perfect for managing the level of socializing that you might want. One quickly learns that there are ALL types of people on the Camino, and you will almost certainly be a person somewhere in the middle of those types.
It is very very common that pilgrims want to walk alone during the day, and the socializing in the evenings is not very hard to handle. Most people are friendly and may reach out to include you in the group. If you find that you are getting too involved with a group, just say you want to walk on your own for a period, or you can decide to stay in a different albergue or town. Such groups ebb and flow and you should not feel obliged. By the time you reach Santiago, you will have met, left behind, passed, re-encountered and re-left many people. Those contacts are mostly ephemeral, which is liberating in many ways.
Contrary to what you might expect, you can enjoy a lot of privacy and anonymity in walking into a different place every night and meeting different people. They expect very little from you, and you have a freedom to be just you. In March you will get started and can develop your own style of functioning on the Camino, without dealing with hoards of other pilgrims.
On the
Camino Frances you need very little Spanish. Everyone will see that you are a pilgrim walking to Santiago, and they will all know what you need, so you don't have to communicate very much.
So, take comfort in knowing that so many (likely most) people set out with similar uncertainties, and most of them settle down by halfway through the first day!