If information about stored WiFi AP or WiFi STA configuration is needed before the WiFi AP is connected or the WiFi STA is activated,  ESP-IDF provides the function esp_wifi_get_config() which fills the structure of the type wifi_config_t

typedef union {
  wifi_ap_config_t  ap;  /**< configuration of AP */
  wifi_sta_config_t sta; /**< configuration of STA */
} wifi_config_t;

wifi_ap_config_t contains information about the stored AP configuration

/**
 @brief Soft-AP configuration settings for the ESP32 */
typedef struct {
  uint8_t ssid[32];           /**< SSID of ESP32 soft-AP */
  uint8_t password[64];       /**< Password of ESP32 soft-AP */
  uint8_t ssid_len;           /**< Length of SSID. If 
softap_config.ssid_len==0, check the SSID until there is a termination 
character; otherwise, set the SSID length according to 
softap_config.ssid_len. */
  uint8_t channel;            /**< Channel of ESP32 soft-AP */
  wifi_auth_mode_t authmode;  /**< Auth mode of ESP32 soft-AP. Do not
 support AUTH_WEP in soft-AP mode */
  uint8_t ssid_hidden;        /**< Broadcast SSID or not, default 0, 
broadcast the SSID */
  uint8_t max_connection;     /**< Max number of stations allowed to 
connect in, default 4, max 4 */
  uint16_t beacon_interval;   /**< Beacon interval, 100 ~ 60000 ms, 
default 100 ms */
} wifi_ap_config_t;

/**
 @brief STA configuration settings for the ESP32 */
typedef struct {
  uint8_t ssid[32];      /**< SSID of target AP*/
  uint8_t password[64];  /**< password of target AP*/
  wifi_scan_method_t scan_method;    /**< do all channel scan or fast
 scan */
  bool bssid_set;        /**< whether set MAC address of target AP or
 not. Generally, station_config.bssid_set needs to be 0; and it needs to
 be 1 only when users need to check the MAC address of the AP.*/
  uint8_t bssid[6];     /**< MAC address of target AP*/
  uint8_t channel;       /**< channel of target AP. Set to 1~13 to 
scan starting from the specified channel before connecting to AP. If the
 channel of AP is unknown, set it to 0.*/
  wifi_sort_method_t sort_method;    /**< sort the connect AP in the 
list by rssi or security mode */
  wifi_fast_scan_threshold_t  threshold;     /**< When scan_method is
 set to WIFI_FAST_SCAN, only APs which have an auth mode that is more 
secure than the selected auth mode and a signal stronger than the 
minimum RSSI will be used. */
} wifi_sta_config_t;

#include <Arduino.h>
#include <WiFi.h>
#include <esp_wifi.h>

void setup() {
  // Start serial connection
  Serial.begin(115200);

  // Get stored information before connecting to WiFi
  wifi_config_t conf;
  WiFi.mode(WIFI_AP_STA);
  Serial.println("Stored STA configuration:");
  Serial.println("========================");
  esp_wifi_get_config(WIFI_IF_STA, &conf);
  Serial.println("SSID: " + String(reinterpret_cast<const char*>(conf.sta.ssid)));
  Serial.println("Password: " + String(reinterpret_cast<const char*>(conf.sta.password)));
  Serial.println("BSSID: " + String(reinterpret_cast<const char*>(conf.sta.bssid)));
  Serial.println("Channel: " + String(conf.sta.channel));
  if (conf.sta.scan_method == WIFI_FAST_SCAN) {
    Serial.println("WiFi scan method fast");
  } else {
    Serial.println("WiFi scan method all");
  }
  if (conf.sta.sort_method == WIFI_CONNECT_AP_BY_SIGNAL) {
    Serial.println("WiFi scan results sorted by RSSI");
  } else {
    Serial.println("WiFi scan results sorted by auth type");
  }
  wifi_fast_scan_threshold_t staTreshold = conf.sta.threshold;
  Serial.println("Minimum RSSI accepted: " + String(staTreshold.rssi));
  Serial.print("Minimum required auth method: ");
  switch (staTreshold.authmode) {
    case WIFI_AUTH_OPEN:
      Serial.println("OPEN");
      break;
    case WIFI_AUTH_WEP:
      Serial.println("WEP");
      break;
    case WIFI_AUTH_WPA_PSK:
      Serial.println("WPA PSK");
      break;
    case WIFI_AUTH_WPA2_PSK:
      Serial.println("WPA2 PSK");
      break;
    case WIFI_AUTH_WPA_WPA2_PSK:
      Serial.println("WPA WPA2 PSK");
      break;
    case WIFI_AUTH_WPA2_ENTERPRISE:
      Serial.println("WPA2 ENTERPRISE");
      break;
    case WIFI_AUTH_MAX:
      Serial.println("MAX");
      break;
  }

  Serial.println("\nStored AP configuration:");
  Serial.println("=========================");
  esp_wifi_get_config(WIFI_IF_AP, &conf);
  Serial.println("SSID: " + String(reinterpret_cast<const char*>(conf.ap.ssid)));
  Serial.println("Password: " + String(reinterpret_cast<const char*>(conf.ap.password)));
  Serial.println("Channel: " + String(conf.ap.channel));
  Serial.print("SSID is ");
  if (conf.ap.ssid_hidden == 0) {
    Serial.println("broadcasted");
  } else {
    Serial.println("hidden");
  }
  Serial.print("Auth method: ");
  switch (conf.ap.authmode) {
    case WIFI_AUTH_OPEN:
      Serial.println("OPEN");
      break;
    case WIFI_AUTH_WEP:
      Serial.println("WEP");
      break;
    case WIFI_AUTH_WPA_PSK:
      Serial.println("WPA PSK");
      break;
    case WIFI_AUTH_WPA2_PSK:
      Serial.println("WPA2 PSK");
      break;
    case WIFI_AUTH_WPA_WPA2_PSK:
      Serial.println("WPA WPA2 PSK");
      break;
    case WIFI_AUTH_WPA2_ENTERPRISE:
      Serial.println("WPA2 ENTERPRISE");
      break;
    case WIFI_AUTH_MAX:
      Serial.println("MAX");
      break;
    }
    Serial.println("Max allowed connections: " + String(conf.ap.max_connection));
    Serial.println("Beacon interval: " + String(conf.ap.beacon_interval) + "ms");
}

void loop() {
  yield();
}

The output would look alike this:

Stored STA configuration:
========================
SSID: NotYourBusiness
Password: WillNotTellYou
BSSID: 
Channel: 0
WiFi scan method fast
WiFi scan results sorted by RSSI
Minimum RSSI accepted: 0
Minimum required auth method: OPEN

Stored AP configuration:
=========================
SSID: Slave:24:0A:C4:81:CE:9C
Password: 123456789
Channel: 1
SSID is broadcasted
Auth method: WPA2 PSK
Max allowed connections: 4
Beacon interval: 100ms

A modified version of this code is in Github Repo.