hi! good decision on getting axies
you are doing good.
remember to give them lots of places to hide, like hollow logs, pots, or even a few mugs.
Make sure the filter is not too strong, a good way is to set it all up and see if your plants move in the current. If they are, it is too strong and you will have to make the flow less, for submersables you can usually get a spray bar attachment which makes the water come out in a sort of shower instead of a big stream. Lots of filters come with them
Also if your plants are live, they will probably need a light to stay healthy and grow. Axolotls do not like light much, so if you have the light on, make sure they have plenty of places to hide away and only have it on for a few hours a day. Some aquatic plants can grow well with little or no light and are great for axolotl tanks so it depends on what type you have. Do a forum search for "axolotl plants" for some good info.
Snails are debatable, i have small pond snails in my tank which hitch-hiked in on some plants and they have never been a problem, but some people say larger snails can be eaten and cause harm much like pebbles.
Bloodworms are good occasionally but earthworms or axolotl pellets should make up the main diet of a healthy axolotl. Bloodworms are also VERY messy, so you can look into a feeding dish or a feeding jar. You just lower them in in the dish/jar and it should contain most of the mess.
Starting a worm farm is a good idea. Its enviro friendly to compost and you will have a lifetime supply of axolotl food. Dont freak out if you can only feed bloodworms rite now, they will not cause immediate harm, just look for a 'healthier' food source when you can.
also with tank size, the bigger the better.Good luck!