If you decide to install gutters on your own, it’s gonna be incredibly difficult. Most of the time, you have to have two people, especially to get the measurements for the runs. Just hanging the gutter itself, trying to hold a long piece of gutter up and get it installed to your house correctly will typically lead to issues.
More than likely you will have to have at least one other person, sometimes even more than that, just depending on your skill level, how long the run is, how high up in the air the run is. There’s a lot of variables that can go into how difficult installing gutter can be.