Hi ,
If your current baseline is 3-4k steps per day, aiming for 10k tomorrow is quite a stretch.
Even though 10k steps per day is a decent target for health and body comp, you probably won't meet that goal right away.
To lower the barrier and increase your chances of success, I'd just start with actually recording your steps consistently to look at your daily average.
Then, add one walk per day that you can easily repeat.