I mean with no additional transportation cost or places I can reach by walk from station.
I'll be going alone so I prefer a safe place for tourist
The Tokyo Wide Pass is an excellent regional pass - if you use it to go as far as you can every day for its 3 day validity, you can save about ¥20,000! As to where to go, there are many day trips you can take on one, including Nikko, Hakone, the Fuji 5 Lakes area, Karuizawa, Kusatsu, Izu, Kamamura/Enoshima, Kawagoe, Takao, Okutama, Yokohama, the Ushiku Great Buddha, Nokogiriyama, Minakami, Showa Kinen Park, and more. You need to choose what places appeal to you most - nobody knows that except you.
If you are referring to within Tokyo, you certainly don't need the Tokyo Wide Pass for that, and you would lose money on one if you only stayed within the city. You could instead use a 48 or 72 hour subway pass and save money that way.
Within Tokyo, most first-timers go to see the Sensoji Temple, as well as Nakamise Shopping St. Plus you should be just in time to see Sensoji's "secret" garden, Denboin, which is only open a couple months a year. But Tokyo has so much more. Shibuya at night is a blast. Akihabara is famous for its electronics and anime. The Harajuku Girls on a Sunday afternoon have been around for decades. And don't neglect Tokyo's many beautiful traditional gardens - Koishikawa Korakuen is one of the best, but there is also Kyu-Shiba Rikyu, Kiyosumi, Rikugien, Hamarikyu, Tonogayato, and many more. You can browse the Tokyo city government's tourism guide for tons more to see and do.
As for safety, Japan is extraordinarily safe. That doesn't mean you should throw away common sense, but you'll be in one of the safest nations on earth.