Your town has a set capacity it can hold of each resource (not your vault) if you go to your palace and click on statistics the on each resource you will see your capacity for each. Until you have less than that amount on hand your town will not produce resources. For example your food capacity is 4.5mil but you have 121mil on hand you will not make food.
To increase ur production u need to have hero set which i think u would have figured out but u also have capacity of total buildings and that can be increased in economics knowledge part but it takes hell lot of rss to do so better leave them after doing them till lvl5 or if u wish to go ahead then ur choice. :))