I may be wrong but I read somewhere that an axolotl can reach sexual maturity in just six months depending on quantity and quality of food. Mine have grown very quickly. I have no feeding routine. I just check every day and make sure there's always food in the tank. Here are some good food choices in size order-
Baby brine shrimp- For newly hatched larvae.
Baby daphnia- Ditto, can set up a low cost hatchery.
Brine shrimp- But they die after about an hour if left uneaten
Daphnia- Good choice as they can live in the tank until eaten.
Bloodworms- Quite messy but axies seem to like them
Maggots- Can be bought in any fishing shop, cheap but turn to castors if not kept cold/refrigerated.
Prawns- Can be expensive especially if you have more than a couple of axies.
Mealworms- Cheap and easy to breed, to stop them floating on the top of the tank feed them slices of carrots every few days.
Earthworms- Can be dug up from your own back garden if you have the time.
Experiment with em a bit they'll love it