What are the skills that a solo co-founder must learn and balance between?

I'm currently a purely technical founder who is working on a SaaS application.

What kind of skills should I also be learning on the side to become a better solo founder and make my startup a success?

I'm not looking to bring on a co-founder and will be going it solo until I get to profitability. At which point I will hire people.

1.) Expect that you will be doing EVERYTHING ELSE

2.) You need to aim just perfectly right. Not too high and not too low.

too high - you will have an impossible mission to achieve.
too low - you will be too late to all of the possible opportunities.

3.) There’s always more to learn every single day.

Before hiring people, you need to consider the following:

1.) How will you pay for the new hire?
2.) Are you being overworked?
3.) Do I need a new and different skills and knowledge?