Ok, you have a lot of questions, let me take them one at a time.
The reason you are getting huge air and landing in the flats is probably because you are taking a huge cut at the wake. I see this many times with beginners, the will take the hardest cut they can at the wake, once they reach the wake, they have no more momentum, thus, sometimes they hit the wake really great and go huge, other times they slide like a slalom skier right over the wake. The reason for this is because you aren't edging all the way up the wake. Start slowly about 5-7 feet from the wake, get harder as you get closer to the wake. Your hardest cut should be at the top of the wake. When your board digs into the top of the wake, it will spring you up when the board releases, this is called pop.
Heelside 180s are tricky, its because you are landing switch toeside, and that's not a normal position for your body to be in. Be sure that you are semi-comfy riding switch. Be sure that when you land you are over your toes, don't reach out with your feet to land, your body should be straight up and down, as if there was a rod going down through your body.
The Detention Series is good like Mike said.
Tricks are up to you. Check out wakeworlds trick list and see if there are any that interest you. I would get the basics dialed first, air(hs and ts), grabs, 180s, grab 180s, etc. Then move on to 360s and inverts.
Board is also another thing that only you can decide. If you like the board, ride it.
A pole and weight will make the wake bigger and allow you to get a bit more air, they aren't necessary.
A toeside wake jump is basically all or nothing. Take a strong progressive edge at the wake, be sure to lean from your hips and not your shoulders, leaning over will do nothing but throw you off balance and hurt your back. Lean in with your whole body and lay your board on edge. Hold that edge through the wake and when you feel the pop, just stand up tall and spot your landing. Don't reach out for the water with your heels, or you will slide out on your butt. You can take it slow and work up to crossing both wakes, but I find it easier to go all out, the landings are much softer.
If I have confused you, feel free to email me and I will answer any other questions.