can I earn by aliexpress affiliate by Instagram?
Can, Yes. Want to? Probably not.
Is there any reason you don’t want to dropship it yourself and take a bigger cut?
yes of course Ig can be used for affiliate marketing stuff you can check here in the forum for multiple ways to do affiliate marketing.
Can you share me some supplier (fashion, associate, gym, home, pets…) at US for dropship?
In the end of the day it’s all about profit margins. Calculate the costs of running the operation and the share of the aliexpress affiliate program. I don’t know about the % but it’s just a guess from my side that you’ll need a good conversion rate on your accounts to make it work.