The error should tell you which line number in your script has the offending invalid characters. With that said,it's a little unclear as where you are writing this new feature class.
The 'out_path' argument for this tool is a path to a given workspace for example:
out_path = r'C:\the\path\to\My.gdb'
Perhaps you could include your full script along with the full error?
CreateFeatureclass_management (out_path, out_name, {geometry_type}, {template}, {has_m}, {has_z},
{spatial_reference}, {config_keyword}, {spatial_grid_1}, {spatial_grid_2}, {spatial_grid_3})
That should just about do it....