@elvisrene10 Big hugs to you. It sounds like this has been really frustrating and upsetting to you. I totally get it. Especially with big kids around.
I will tell you, that I've fit 2 year olds in carriers for the first time. He may have even been 3, it was a long time ago and my memory is fuzzy, and his little sister was about to be 1. Mom really needed to contain both of them for different reasons. They came back to my meetings month after month and she'd just keep trying new things. She was very excited. And both kids adapted quickly.
More often I'd see 3, 6, 8, 9 month olds getting worn for the first time. I think someone here was asking for advice recently wearing their 18 month old for the first time through the airport. It's never too late. Many people don't start wearing until after the newborn stage because hormones are high and baby can be finicky and it's just too hard.
Which Tula do you have?
Practicing with others may actually be stressing you both out more. If the carrier is fit correctly, baby fed, changed and not sleepy before going in and still super upset, go for a walk outside, even if you just stand on the porch for a minute. Stand next to a running faucet or vacuum or hair dryer. Anything that's kinda loud but good constant sound. Pat their butt kinda hard and bend your knees to bounce them or sit in a yoga ball if you have one. Talk to them in a voice to distract them, like pointing things out in your environment or anything that comes to your mind.
Some babies just need time to get used to it and taking them out immediately doesn't give them the chance to do that. I've had people get fit at the start of a loud meeting with a crying baby and they just walk around until they calm down. Sometimes they never do and we try s different carrier and sometimes they just needed to pass out and realize that this is actually pretty great.
It's a skill to learn for sure for both you and baby. It's super helpful and I want you to love babywearing. Let me know what questions or feelings you are having.