How to Create customer and add new address programmatically in magento 2?

To create customer and customer addresses programmatically in Magento 2, You need to study the entire article and implement the code in your website.

Given the below code checks, the Customer exists or not using the email id. If the customer is new, Add a new customer and add the given address to the same customer otherwise display an already existing customer message.

<?php
$customerInfo =[
    'customer' =>[
        'firstname'    => 'Rakesh',
        'email'        => 'rakesh.jesadiya@aaaa.com', //customer email id
        'lastname'     => 'jesadiya',
        'password' => 'admin123',
        'prefix' => 'Mr',
        'suffix' => ''
    ],
    'address' =>[
        'firstname'    => 'Rakesh',
        'lastname'     => 'Jesadiya',
        'prefix' => 'Mr',
        'suffix' => '',
        'street' => 'Abcd street',
        'city' => 'Los Angeles',
        'country_id' => 'US',
        'region' => 'California',
        'region_id' => '12', // State region id
        'postcode' => '45454',
        'telephone' => '1234512345',
        'save_in_address_book' => 1
    ]
];

$block->createCustomer($customerInfo);

In the Block file, Pass customer-required data from the above $customerInfo array,

<?php

namespace Rbj\CreateCustomer\Block;

class CustomerAddress extends \Magento\Framework\View\Element\Template
{
    public function __construct(
        \Magento\Framework\View\Element\Template\Context $context,
        \Magento\Store\Model\StoreManagerInterface $storeManager,
        \Magento\Customer\Model\CustomerFactory $customerFactory,
        \Magento\Customer\Api\Data\AddressInterfaceFactory $dataAddressFactory,
        \Magento\Customer\Api\AddressRepositoryInterface $addressRepository,
        array $data = []
    ) {
        $this->storeManager = $storeManager;
        $this->customerFactory = $customerFactory;
        $this->dataAddressFactory = $dataAddressFactory;
        $this->addressRepository = $addressRepository;
        parent::__construct($context, $data);
    }

    /** Create customer
     *  Pass customer data as array
     */
    public function createCustomer($data) {
        $store = $this->storeManager->getStore();
        $storeId = $store->getStoreId();
        $websiteId = $this->storeManager->getStore()->getWebsiteId();
        $customer = $this->customerFactory->create();
        $customer->setWebsiteId($websiteId);
        $customer->loadByEmail($data['customer']['email']);// load customer by email to check if customer is availalbe or not
        if(!$customer->getId()){
            /* create customer */
            $customer->setWebsiteId($websiteId)
                    ->setStore($store)
                    ->setFirstname($data['customer']['firstname'])
                    ->setLastname($data['customer']['lastname'])
                    ->setPrefix($data['customer']['prefix'])
                    ->setMobile($data['customer']['mobile'])
                    ->setEmail($data['customer']['email'])
                    ->setPassword($data['customer']['password']);
            $customer->save();

            /* save address as customer */
            $address = $this->dataAddressFactory->create();
            $address->setFirstname($data['address']['firstname']);
            $address->setLastname($data['address']['lastname']);
            $address->setTelephone($data['address']['telephone']);

            $street[] = $data['address']['street'];//pass street as array
            $address->setStreet($street);

            $address->setCity($data['address']['city']);
            $address->setCountryId($data['address']['country_id']);
            $address->setPostcode($data['address']['postcode']);
            $address->setRegionId($data['address']['region_id']);
            $address->setIsDefaultShipping(1);
            $address->setIsDefaultBilling(1);
            $address->setCustomerId($customer->getId());
            try
            {
                $this->addressRepository->save($address);  
            }
            catch (\Exception $e) {
                return __('Error in shipping/billing address.');
            }
        } else {
            return __('Customer is already exist!');
        }
    }
    
}

Run the indexer command to see a customer in the admin panel,

php bin/magento indexer:reindex
php bin/magento cache:flush