There are a lot of things to do in Gwalior on a weekend. Gwalior is a really lovely town. You can go sightseeing in the city. You can visit Gwalior fort, Sasbahu Temple. You can spend some time at the Gujari Mahal Archaeological museum. There is an option to enjoy boat rides in the Tighara dam.
In Jiwaji, there aren't many options for activities other than sports and NGOs. But, Jiwaji University has a pretty large sports stadium. You may make use of it. If you are a sports enthusiast, try playing basketball at the sports center or go jogging along the Oxygen path.