Teaching of any kind is something that can have a pretty steep learning curve. Nobody is expected to teach the perfect class at the first attempt. That being said, there are ways to do things and ways not to do things. Making sure that you approach your first class properly will at least give you a better chance of producing something decent.
Not only that, but if you don't set things up properly in the beginning, then you could cause yourself more trouble in the long-term (more on this later).
The following five tips are guaranteed ways to make your first class a nightmare, so do your best to avoid them.
Tip 1 - Not Preparing Your Class
If you want your first class to be terrible, unstructured, and a waste of everyone's time, then you shouldn't plan it at all. However, if you like to think that you have a bit of pride in your job, then you'll write one out.
It's one thing to have a rough outline in your mind, but if you write out a full plan you will be able to keep the lesson flowing well, even when things don't go according to that plan. If an activity isn't working or students are misbehaving, you can simply end it, look down at your plan, and move on to the next step.
Not only that, but you can also have a list of "emergency" or "extra" games/activities at the bottom of your plan as a good contingency for getting your timings wrong.
Plus, later on when you are trying to figure out what makes a good or bad lesson, you can review previous plans and notice patterns.
Tip 2 - Try To Be Your Students' Best Friend
Every teacher wants their class to like them, and it can be very easy to go into a class as the students' friend. Doing this can have some long term disadvantages though. It can also lead to unruly or undisciplined students, as they don't fear your wrath or even consider you a "real" teacher. If you're a foreigner, which you most likely will be, then this can be even stronger.
It's still more than possible to have students LIKE you without them thinking of you as an older brother or sister though, so don't feel like you have to come in to the class guns blazing and acting like a drill sergeant.
Think long term here. It's a lot easier to set boundaries, rules, and earn respect from the beginning than it is to suddenly try to enforce rules later. Not only that, but students are often more well behaved in the first few classes while they test the waters with their new teacher. You might think you've got a class full of angels and you can be their friend, but just wait until two months later!
Tip 3 - Show Off Your Local Language Skills
Sometimes you want to show off that you know a few words of their language (especially if you're trying to be their best friend!) and other times you just think that a quick translation of some target language is necessary to help the students learn.
While the latter might be the case sometimes, it's also going to be detrimental in the long term. As soon as students know that you can speak some of their language, they'll stop trying so hard to understand new vocabulary and will just wait for a translation. This makes it much harder to learn, defeats the whole point of English immersion, and also makes your job slightly less necessary!
Tip 4 - Don't Prepare Any Backup Activities
If you don't want things to go smoothly, then you definitely shouldn't plan any backup activities. This was touched upon earlier, but to go into more details, nothing ever goes to plan. Sometimes a task will take longer than you thought, meaning a later activity has to be abandoned. Other times, you'll whiz through a task and find yourself staring at the clock willing it to go faster.
There's only so many times you can play hangman until class finishes, so you really ought to prepare some backup games/activities. Don't be lazy and do "just enough" if you want things to go well.
Besides, if you end up not needing those backup activities, you can just use them in the next lesson instead. Even lazy people can benefit from this!
Tip 5 - Overestimate Your Own English Skills
Lot's of native English speakers assume that their English is perfect and they know the language inside out. They'd be wrong! Like most languages, English is infinitely more complex than you can imagine, and a lot of the rules you follow are done so subconsciously. There will be plenty of times when someone asks you about a grammar rule or piece of vocabulary, only for you to realize that you aren't sure of the answer, or worse, you're wrong about it.
To counter this, pay attention to the language you're teaching, make sure you fully understand it, and if you're teaching adults, arm yourself with a decent grammar book!
Don't Use Common Sense
Apart from some of the "long term" tips mentioned above, which are only notable after you become an experienced teacher, most of what we've covered in this article is just common sense.
So on that note, if you want your first class to be terrible, then you should throw that common sense of yours out of the window.