Because many of the topics are the same for group or solo, here is my short list for you to peruse;

It is generally safer to go in a group (although some groups...). On your own, YOU are the one who needs to recognize when you need to stop and take care of yourself for whatever ails you at the time. No one else will stop you and say "Dude, your lips are turning blue. We need to stop and get you warmed up." You need to develop a system to recognize these things in yourself before you push it too far whatever the cause is. Understand what health problems can occur and why. Understand your limitations.

Navigation. Don't be a part timer on this. Know how to stay found where ever you are.

Get a personal locator beacon for your families sake. Except for this, the rest of your gear is likely going to be the same as usual.

Each journey starts with a single step. Don't try to skip steps on your journey and only you will know what these are. Don't be in too much of a rush in this.

Oh, and don't be worried if you start talking to yourself on these solo's. You will stop this as soon as you get back to civilization. Of course if you bring a dog like I do, you will have someone to talk to after all.