The National Heritage Lottery Funding granted £1.4m last year to Dudley Council and the Friends of Stevens Park.
Cash will be used to fund the restoration and extension of Tintern House and to enable wider park improvements.
The disused building, which was formerly known as the White House, will have a community café, new toilets and meeting rooms added as part of the first phase of works by selected contractors Speller Metcalfe.
The Emily Jordan Foundation, a charity working to support people with learning disabilities, will operate from the building.
It will be developing horticultural training opportunities, a bike recycling workshop as well as other opportunities to support people with learning disabilities to move closer towards work.
Park improvements including heritage interpretation, new access to the Memorial garden, new footpaths and planting will follow.
It is expected that a community development officer will be appointed in the future to deliver a range of activities and events.
Councillor Karen Shakespeare, cabinet member for public realm, said: “Dudley Council is committed to preserving and maintaining our parks and green spaces and the pandemic has highlighted just how vital they are to our collective wellbeing.
“The new use of the former White House building will have huge benefits to people with learning disabilities.”
Chris Jordan, chair of the trustees of The Emily Jordan Foundation, said: “We are all looking forward to opening our service provision at Stevens Park.”