I want to buy 1 year Ubuntu Advantage subscription for 1 desktop. I actually do not need support, but I need Landscape. I want to manage all my office computers through Landscape. Are there any limitations in Ladscape? How many computer can I connect to Ladscape?
The number of licenses you'll need to get is dependent on the number of systems you want to manage - 1 Desktop subscription includes support for one desktop plus landscape management for one desktop. Similarly, 10 Desktop subscriptions get you support for those 10 machines, and nothing more.
If you have an entire set of machines (say, 25 desktops, and 3 servers) you want managed, you'll have to purchase enough subscriptions to cover all those systems. There's no easy way around that.