Create a VPC network and Attach 4 Subnet, 3 Private and 1 public subnet.

 In the aws dashboard search for virtual private cloud. then click on create VPC

Fill 10.0.0.0/16 in IPv4 CIDR

Click on create VPC

Once VPC is created, go to subnets and click on create subnet

Create four different subnets in different availability zones

Click on create subnet

So all the respective subnets were created

now create Internet gateway, for this we can use the existing gateway or create new

Attatch the gateway created to a VPC

the VPC attatched can be viewed

Now let's create the Route Tables

Now inside the route table, edit subnet associations

Create another route table for Public subnets

configure the public route table to route all requests to the ISP

Now all the subnets in vpc are ready. let's launch the EC2 instance of each public and private ec2.

Create a fresh EC2 instannce, chnage the VPC and subnet in network settings

similarly create a new instance in VPC again with public subnet

 

also setup security group rules

Now the public subnet can be accessed via public ip