Julie, I'd be surprised if you don't have hundreds of walking partners to choose from in the month of June, all within a few days, and starting day one. If you are, as you say, extremely easy to walk with and have no set agenda you would be hard-pressed to remain alone, even if you were Greta Garbo.
Others may disagree, of course, but I would not commit in advance to walking with one stranger when there are so many potential friends thronging the Way. Every albergue, every cafe, and the track, above all, will be alive with friendly pilgrims in June. There are also some serious types and introverts who are less eager to socialise, but sometimes they make great companions with a little patience. If you find you prefer a different pace or different company, you'll find alternative comrades almost immediately.
For many, making friends on the Way is as easy as shooting fish in a barrel. Except you must not shoot the pilgrims!
Excited for you
Rob