Your first question is related to your main problem. Yes, it is indeed extremely difficult, if not impossible, to have a WILD when you're going to bed for the first time. This has to do with the fact that at that point, it'll take about 90 minutes until you reach your first REM-stage of sleep. Since this is the only stage of sleep in which you dream, you have to get the chance to enter it quickly after falling asleep. This is why people do it in the morning. At that point most of your deep (or delta) sleep is through and you'll be having more REM-sleep. It is therefore much easier to have a WILD at that point.
You can't dream without REM-sleep and so you can't WILD when you aren't in REM-sleep. SP and HI are both reported to be possible experiences, which makes sense as they are things you experience before the dream kicks in. The (Waking Initiated) Lucid Dream itself however, will not come until you've conciously gone through a black period of deep sleep and go into REM-sleep. This is no problem when that process will take a couple of minutes or seconds, but it will be when it takes 1½ hour.

As for your question on HI. You'll know what it looks like when you experience it. It can come in actual shapes representing things, or just abstract forms consisting of light. It's really not that important to be able to recognize them. The only thing really need to know is that they're there, so that you don't get startled or carried away when you see them, but instead stay calm and keep feeling like you were.

Hope that helped, sorry for the long post. I tend to use a lot of words in order to explain things the best I can. >.>


Edit: Zomg, BillyBob beat me to answering the questions. All that typing for nothing. Oh well