write CloudKit records for field string values

I am trying to fetch my CloudKit record and then update it with new data.
I have imported CloudKit framework I have added CloudKit and key/values to my capabilities. I have put them into my entitlements. I have use Schemas to create new custom type private records and added 5 fields. I would like to know how to update these field strings in my iphone app and then get that information on my watch app and put the data in text labels.
I have tried various things but nothing seems to be working. I am working in objc. Could someone help me.
Here is some code I am trying to get to work but with little success. As a 68 yr old retired art teacher teaching myself this I am not a trained coder and need all the help I can get.
I just tried this and it runs through, but I can't see where I put in the values for the keys I have put in. Where do I put those values to modify.

Code Block 
 NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];
        [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
        // or @"yyyy-MM-dd hh:mm:ss a" if you prefer the time with AM/PM
        NSLog(@"%@",[dateFormatter stringFromDate:[NSDate date]]);
        NSString *date =[dateFormatter stringFromDate:[NSDate date]];
        NSString *myPoolString = @"MyPoolInfo";
        NSString *MyPoolInfoString = [myPoolString stringByAppendingString:date];
        NSLog(@"MyPoolInfoString:::%@",MyPoolInfoString);
        CKRecordID *recordID = [[CKRecordID alloc]initWithRecordName:myPoolString];
        NSLog(@"recordID:::%@", recordID);
        CKRecord *record = [[CKRecord alloc] initWithRecordType: @"Pool" recordID: recordID];
  [[CKContainer defaultContainer].privateCloudDatabase fetchRecordWithID:recordID
                         completionHandler:^(CKRecord *record, NSError *error) {
            NSArray *myFields = [NSArray arrayWithObjects:@"temperature",@"date",@"level",@"trip",@"battery",nil];
          
            CKModifyRecordsOperation *modifyRecords= [[CKModifyRecordsOperation alloc]
                             initWithRecordsToSave:myFields recordIDsToDelete:nil];
            //[modifyRecords setValue:self.myTrip forKey:@"temperature"];
            //[modifyRecords setValue:self.myDate forKey:@"date"];
                      modifyRecords.savePolicy=CKRecordSaveAllKeys;
                      modifyRecords.qualityOfService=NSQualityOfServiceUserInitiated;
                      modifyRecords.modifyRecordsCompletionBlock=
                           ^(NSArray * savedRecords, NSArray * deletedRecordIDs, NSError * operationError){
            //   the completion block code here
                               [record setObject: self.myTemp forKey: @"temperature"];
                               NSLog(@"savedRecords:%@",savedRecords);
                        };
                      
            
            [[CKContainer defaultContainer].privateCloudDatabase addOperation:modifyRecords];
         }];

Like I said I have set up a private database Pool and a CKRecordID MyPoolInfo and fields but I am totally lost. There is very little out there for people working in objective-c.

HELP