NOAA can get you lots of data, it's a good first starting point. Setting the right options for orienteering mapping, ordering a point cloud (LAZ file) or generating contours (.DXF to import to OCAD, OpenOrienteeringMapper) and also getting aerial imagery (GeoTIFF which you can import into OCAD or OpenOrienteeringMapper as a georeferenced image)
If the data isn't available at NOAA, you might find it at OpenTopography. You can also access the same data and process it with OpenTopography's tools, so it's worth coming here even if you get data from NOAA.
From CalTopo we can generate Georeferenced maps with trails, contours, buildings, aerial photos from different sources, and they all come with magnetic declination info.
Take Screenshots! Process them... Then adjust to fit the georeferenced images in OCAD or OpenOrienteeringMapper. The Strava Global Heatmap is useful for identifying trails, especially underneath forest canopy
EarthExplorer: Another source for aerial photos. You can also try county and city government websites if the national sites don't have recent enough aerial imagery.
National Map Viewer: Another place for LIDAR. If none of the national sites have LIDAR for the area you want, you can try the county or the city government websites also. Maybe contact someone in the relevant city department if you can't see anything online.
OpenOrienteeringMap online: Get Satellite data contours (SRTM or GLO) at up to 5m intervals, if you don't have LIDAR data for an area. And this will also calculate the magnetic declination for you with grivation. Generate PDF, JPG, JGW (JPEG World file) and you can then convert the PDF for import as a GeoTIFF into OCAD or import the JPG+JGW into OpenOrienteeringMapper.