cannot access to EC2 instance

Hello.

Is there an internet gateway attached to your VPC?
If you have not created it, please create it by following the steps in the document below.
https://docs.aws.amazon.com/vpc/latest/userguide/working-with-igw.html

Also, make sure that the route table for the subnet where EC2 is running has a route to the internet gateway configured.
https://docs.aws.amazon.com/vpc/latest/userguide/WorkWithRouteTables.html

If the network ACL settings have not been changed from the default settings, all communication should be permitted, but if the settings have been changed even once, please check again.

I don't think it's very relevant, but I think it will be useful when you create RDS etc. in the future if you also enable the DNS settings of the VPC.
https://docs.aws.amazon.com/vpc/latest/userguide/vpc-dns-updating.html

You need to create an Internet Gateway (IGW), associate it to your VPC, and add route on the subnet of your instance to reach 0.0.0.0/0 via the IGW.