Need to run select statement across all databases
Here's the "do something on each db" template I use, slightly adapted to your example:

--Create a table to hold the query results
CREATE TABLE #licenselist
    (dbid smallint, dbname sysname, system_license varchar(99));

DECLARE @fixedname nvarchar(150);

--Include or exclude whatever databases you want
DECLARE dbCursor CURSOR FOR
    SELECT REPLACE(QUOTENAME(name),'''','''''') --For db names with annoying characters
    FROM master.sys.databases
    WHERE state_desc = 'ONLINE'
    AND HAS_DBACCESS(name) = 1                  --Added at @SolomonRutzky's suggestion
    AND name NOT IN ('master','msdb','model','tempdb');

OPEN dbCursor;
FETCH NEXT FROM dbCursor INTO @fixedname;

WHILE @@FETCH_STATUS = 0   
BEGIN   
       EXEC ('USE ' + @fixedname + ';' + 
        'INSERT INTO #licenselist
         SELECT DB_ID() as dbid, DB_NAME() as dbname, ParamValue as system_license
         FROM Table1 
         WHERE paramname = ''SYSTEM_LICENSE'';');

       FETCH NEXT FROM dbCursor INTO @fixedname;
END;   

CLOSE dbCursor;
DEALLOCATE dbCursor;

SELECT * FROM #licenselist 

DROP TABLE #licenselist


EDIT: streamlined a bit, removed the raw @dbname variable and instead fixed it in the original query.