I would rather simply enjoy what Christmas was originally supposed to be, and that is a pagan festival honoring the sun. It is supposed to be fun and joyous, along with a measure of stress that is necessarily associated with preparation. There are so many correct ways to celebrate Christmas that it is beyond judging anyone for "getting it wrong".
Even if you are worried about screwing something up, try anyways. Chances are, if you just get a Christmas tree and decorate it cold, it will be wimpy. You are probably going to underestimate the number of lights and ornaments needed to properly decorate it. You are probably also going to get it to turn out sloppy, unbalanced, and out of sync with decorations elsewhere in the room. You only need worry about basic safety at first--no letting a real tree dry out (this is the most important rule, since a dry tree is much easier to set on fire than a well watered tree), no using open flames on your tree, use miniature or LED lights that burn cool, reading the safety directions on the light string box, and not placing glass ornaments where they can get busted and become a hazard.
Sure, it looks nothing like those professional displays you probably seen advertised. But, neither do most stores these days--I have seen so many store displays looking wimpy as of recent years. Also, as this is your first attempt, try to log what went wrong. Did the tree look skimpy on lighting? Did it look unbalanced? What about the ornaments? Was it out of sync with other decorations? You are going to need to keep a log on this, buying more ornaments you see fit that would fix the problems. Note how many lights you put up this year--if they look wimpy, you might double or triple the number. Usually, people start with 500-600 miniature lights on a 2 meter tree. Generally, "too many" undersized lights is better than larger but fewer lights on your tree.
Some shortcuts can be found looking at YouTube videos. There are many videos there on setting up your tree, and you can incorporate some or all of what you see there. Generally, you will need at least double the number of ornaments you think you need if this is your first time, and it will still look wimpy. The pros work in lights all the way to the center of the tree, and they can use huge numbers of undersized lights (as many as 80 boxes on a 2 1/2 meter tree). They work lights out and back along each branch, and each green along the branch, to do this. They are able to place as many as 400 or 500 ornaments on that tree, or more, placing some in the middle of the tree (use the plain ones near the middle and the fancy ones outside). And use LEDs--though they are more expensive, they are less prone to blowing fuses and giving you your $500 light bill.
It matters not whether you keep it simple or go all out. Better to gather the gifts during the year, when you can pay as you go instead of running up a whopper of a credit card bill. You might keep it simple, or you might decide to splurge. The same with the Christmas cards and music. Some will skip the Christmas carols, while others will play them. Some will enjoy the food--the only thing I give a Bah! Humbug! to is drink driving. Many like their decorations simple and will use fewer but bigger lights on the tree along with fewer ornaments. Others go ballistic with decorating everything.
And, some will leave Jesus out of the holiday while others will make Jesus the centerpiece of it. That is the nice thing about Christmas--no "one size fits all". If you like the religious aspect, you will probably head to church and have more Jesus type decorations. If you are atheist, Satanist, or simply don't go big with Jesus, your Christmas tree will probably be more Santa themed, winter themed, or simply display the joyful colors. You might spend more time opening Christmas presents, cooking and eating, and having fun than thinking about Jesus. Others will simply enjoy their families and a little peace and quiet for a change. As before, the only thing I give a big fat Bah! Humbug! to, besides the witlesses knocking on doors holding up children's present opening time, is drink driving.