Step tracking

As far as I know, the only way to add steps manually is to estimate the pace and duration of walking, and log walking as an exercise in the cardiovascular section. If it's daily life routine walking, I personally wouldn't do that: I'd set my activity level based on my average weekly amount of walking. I'd only log walking as exercise if it were done intentionally for exercise, and a steady walk of X minutes at a particular average pace.

Keep in mind that if you get a calorie goal from MFP, it already assumes some amount of daily life activity that burns calories, and that would include walking incidental to things like job, home chores, etc. Logging those steps for calories - as described above - risks giving ourselves double credit for the daily life walking calorie burn. If the goal is weight loss, that might not be ideal.

There is no way to record steps just to track them. Well, I guess you could use web browser MFP to add a custom "additional measurement" via the Home/Check-In page. After the custom measurement type is added, I believe you can update it in the phone/tablet app, too, via the Weight & Measurements item in the More menu. I know that used to be possible before recent changes in the app, but I haven't tried it lately.