How to start? Any help needed

[asp2403]

Hello!
I'm new to OCPP and I have significant difficulties to start diving in subject, any help will be highly appropriated.
I need to write a kind of monitoring tool which should connect to charging station via OCPP and get a set of parameters from it. For example, max charging power, current charging percentage etc.
I use online OCPP charging station emulator (https://cs.ocpp-css.com/ocpp (login: demo, password: demo), https://github.com/apostoldevel/ocpp-cs) to test my development.
I was able to connect to the station and pass through the authorization. But I don't know what to do next. How to get parameters?
Here is my code based on your tutorial (I use java).

private static void testOcppConnection() throws ConnectException {
        final var chargePointId = "EFACECQCTEST";
        ChargePointOperations connection = ApiFactory.Companion.ocpp16ConnectionToCSMS(chargePointId,
                "ws://ws.ocpp-css.com/ocpp",
                TransportEnum.WEBSOCKET,
                null,
                null,
                Collections.emptyList(),
                new OcppCallbacks());

        connection.connect();
        final var idTag = "demo";
        var authResponse = connection.authorize(new RequestMetadata(chargePointId, null), new AuthorizeReq(idTag)).getResponse();
        if (authResponse.getIdTagInfo().getStatus() ==  AuthorizationStatus.Accepted) {
            log.info("Auth accepted");
            var transactionResponse = connection.startTransaction(new RequestMetadata(chargePointId, null), new StartTransactionReq(1, idTag, 0,
                    Instant.Companion.fromEpochSeconds(java.time.Instant.now().getEpochSecond(), 0), null)).getResponse();
            var transactionId = transactionResponse.getTransactionId();
            log.info("Start transaction: {}", transactionId);
            log.info("{}", transactionResponse.getIdTagInfo());
            //What to do next???
        } else {
            log.info("Auth rejected");
        }
    }