I selfishly wanted to walk my Camino alone. Not alone alone, but without anyone I knew. I felt that my first Camino needed to be experienced without any social safety nets, and as I have said before, I did not want to be responsible for anyone else's Camino Experience. I've travelled with groups of friends before and it is not always pleasant.
I think I have convinced my sister to join me for a short Camino Ingles next year after I have finished Camino Portugues and there will be many adjustments I will have to make for that to work. We have already started conversations about walking separately for periods during the day and as she is older, less fit and diabetic, I've insisted she speak with her physician and warned her that she will have to carry some food with her. She's a notorious overpacker, so I will have to go through her pack prior to my flying out to weed out some of the junk she will insist on bringing with her. I have mentally prepared myself to have to mail some things of hers to Santiago to pick up when we're done. lol As siblings there are a lot of things for us to argue about lol. She joined me last year for touristing after my Camino and we holidayed this year together so we both have a pretty good idea of how we travel together. I'm bossy, she's stubborn
As others have mentioned have conversations NOW with your travel companions. What do you each want out of Camino? Are you willing to acknowledge and grant each other's needs or desires for alone time? What is the plan if one of you decides 3 days in that this isn't as fun as they thought and wants to stop walking? (My personal opinion on this is the person who does not want to walk can bus to the next town and everyone meets up there for lunch/drinks/etc or...they can go home). There is also the issue of Covid and some sort of plan should be in place if that happens (hunker down for a few days, bus a few town ahead if schedules are tight, go home if it took a hole punch to your lungs etc) How are shared expenses (eg hotel/pensiones/posadas vs albergues) to be divvied up - and on that issue, if they decide to bail all expenses will fall upon those remaining, so be prepared to pay for your entire Camino. We all have our own preferred walking speed and slowing down to meet that preference is easier than trying to keep up, if the goal is to all walk together all the time than the slowest person dictates the pace.
There are millions of parameters and options for planning to walk Camino, with or without companions, and everything will get thrown out the window when you get there and new options and issues will arise then.
But, having some sort of plan can help keep things as pleasant as possible.
Buen Camino!