The obvious place to stay would be the Hotel Presidente Luanda as it is walking distance to the Port. It however remains an expensive place to stay and I think there are better options.

The Intercontinental is nicer and is also close. The Epic Sana is also an option but is probsbly the most expensive hotel in Luanda. If you want cheaper options the Tropico or Continental might be worth considering. Traffic isn't too bad these days in Luanda and with ride hailing apps like Heetch (probably the most popular in Angola) you can easily get to the port from these hotels. The Thompson Art House Hotel on the Ilha is basic and cheap and would be an option if on tight budget.

There are a bunch of taxis at airport who will transfer you. It is difficult to use Heetch at airport. Alternatively you can pay a premium and have your hotel send a car.