Start with two or three days

Photo: Ermell / Wikimedia Commons / CC BY-SA 4.0.
For a first visit, give Shanghai two or three days. Two days can hold a strong first look: the river, one neighborhood on foot, and the old city. Three days gives you room to slow down, stay longer in a neighborhood you like, or add one more part of the city without turning the trip into a checklist. Neither version is an attempt to see every major attraction.
Shanghai Disneyland does not fit inside those days as one more stop. The resort sits outside these central neighborhoods and asks for a day of its own. If it is a main reason for coming, plan it separately. If it is not, leave it out.
See Shanghai in three parts
You do not need to see all of Shanghai to understand why people like it. Three parts are enough, and they are different experiences, not equal stops.
The Bund and the Huangpu River. The Bund is a protected waterfront in central Huangpu, about 1.5 kilometers along the west bank of the Huangpu River. Historic commercial buildings face the water. Across the river, Pudong’s towers are the newer skyline. That contrast is the first-visit view, and the promenade is enough to see it. An observation deck is optional. Go up only if the view from above is something you specifically want.
Wukang Road and Anfu Road. Wukang Mansion is where people stop for a picture. It is not the visit. The Wukang Road-Anfu Road district is a walking neighborhood in Xuhui’s Hengfu historical area, about 1.5 kilometers between Wukang Road, Middle Huaihai Road, Anfu Road, and Wulumuqi Road. Plane trees, older houses, cafes, and small shops are the reason to come. Walk the streets. Do not end the outing at one building.

Yu Garden and the old city. Yu Garden is a Ming-dynasty garden at 168 Fuyou Road, beside the City God Temple. The temple, the lanes, and the Yuyuan shopping streets connect to it, and they are not the garden. The garden is a bounded historic visit. The streets outside are the crowded old city, with shops and snacks. Enter the garden if you want the classical garden itself. Stay outside if the streets, shops and temple area are what interest you more. Do not use one name for both.

One easy first day
Use one sequence, not a clock. Start on Wukang Road and Anfu Road while daylight makes the walk the point. Then go east by metro or DiDi to Yu Garden and the old city. From there, continue to the river and finish on the Bund after dark, when the skyline is the reason to be on the promenade.
The order follows the map. Wukang Road and Anfu Road sit well west of the water, so they are not a casual stroll from the Bund. Yu Garden is already in the old city, close enough to the waterfront to continue on foot. You cross the city once, then stay near the river for the rest of the day.
A regular Huangpu ferry can add a few minutes on the water without turning the crossing into a sightseeing cruise. Check the route you want on the day rather than building the whole evening around it.
Keep the stops to these. A first visit also spends time on navigation, food, payment, and finding the right metro exit. Leave room for that. The metro handles most of these moves easily; DiDi is useful when you would rather go door to door.
Stay where Shanghai is easy
Stay in one of three areas. Choose by what you want nearby.
Central Huangpu, around People’s Square. This suits a first visit that wants the simplest metro base. People’s Square is a main interchange, and Nanjing Road leads from this part of the city toward the Bund, so that walk can sit inside the day rather than beside it. The trade-off is a busier, more commercial neighborhood.
Jing’an. This suits someone who wants a central base with straightforward metro access, a little removed from the main sightseeing streets. The Bund and Yu Garden are a short ride, not downstairs. That distance is the trade-off.
Xuhui, around Wukang Road and Anfu Road. This suits a visit built on walking that neighborhood, on the former French Concession side of the city. You will ride to the river. If those streets are the part you most want, the ride is the cost of staying there.
Don’t try to add everything
Do not give every famous place the same share of the day.
Nanjing Road is worth walking if you are already between People’s Square and the Bund. It is a commercial street on the way. It does not need its own morning simply because it appears on every Shanghai list.
Observation decks are reasonable when a view from above is the thing you want. They are not required for understanding the city. The Bund already shows the river, the older waterfront, and the towers across the water.
Shanghai Disneyland is a real day out, away from the neighborhoods above. Add it by giving it that day. Do not attach it to a day that is already holding the Bund, the old city, and a neighborhood walk.