Horizon 2020 is the title of the eighth EU Framework Programme for Research and Innovation. Horizon 2020 has a duration of seven years (2014-2020) and it has a budget of about 76 billion Euro. Horizon 2020 comprises all relevant research and innovation programmes of the European Commission.
Project proposals for centrally coordinated EU funding programmes such as Horizon 2020 are submitted via the Funding & Tenders Portal. Moreover, it is used for managing funded Horizon 2020 projects. The portal provides e.g. a key word and context search. You need a user account ("EU Login"), if you want to use the various fundctions of the portal.
The Work Programme 2018-2020 describes all Horizon 2020 call topics in detail. The Work Programme also contains other information e.g. the call budgets.
The EU Office provides you with more information on the websites Calls for Project Proposals and Horizon 2020 proposal phase.
Furthermore, several information events are offered familiarizing you with the funding structure and funding rules of Horizon 2020. You will find an overview here.