High Ammonia... Help?

Hi, and thanks in advance for any advice! Please be kind as this is my first time with an axie, so I'm a complete beginner.

I got my axie about 2 weeks ago. It was, unfortunately, a bit of a rushed decision because I spotted the "perfect" one and fell in love. Long story short, my tank wasn't properly cycled when I brought him home. Needless to say, I'm regretting that decision now.

Anyway, my ammonia is high, and I can't seem to get it to go down. Most mornings when I wake up, it's 4.0. I've been doing daily 50% water changes to try to control it, but it doesn't seem to be helping. My other numbers are...

PH: 7
Nitrite: 0.25
Nitrate: 0

My tank is 10 gallons. I don't have any loose substrate. I have live duck weed, bamboo and a Marimo moss ball. My axie is a juvenile, about 3 inches. He seems to be acting fine - Eating well and no signs of stress, yet. My temp hovers right around 64. I am using a canister filter.

Any advice would be greatly appreciated!

I would strongly suggest you move your axie to a tub while you cycle your tank - that level of ammonia will do a lot of damage.
Follow the guides on here for cycling, but it is likely to take a cpuple of weeks or more - be prepared for daily tub changes for your axie.

How should I go about the tub changes? Should I have two tubs that I can alternate between from one day to the next? And what would be the best way to transfer him? A net?

Yes - 2 tubs is a good system. Net or hands is fine for moving an axie.

Okay, thank you for the advice. I will get him out of there right now. I feel dumb getting him before cycling the tank, and I don't want him to suffer because of my abrupt decision making!