I'm a new player as well, almost a week old now (but my concept of time isnt really accurate, so probably less) so while my advice likely isn't the best, here's what I've come up with so far:
Don't worry about points when you're starting out; instead go for progression. This way, you're more likely to complete your quests faster, getting amazing items (See: Armageddon) and without completing your quests you don't stand a chance (as a newbie) to get a worthwhile score, anyways.
This also means taking

out of order, trying to complete it ASAP, because it gives you an extra life and clears the level. If you're going for points and go C-R-I-S-T-A-L, you get 150,000 bonus points, but I feel that in the longrun you're more likely to survive by getting as much

as possible.
Make sure you get all the items you want from the level before killing the last monster. If there's a chance that killing one of them will finish off the other by accident, don't risk it. On every level, you'll first see an effect item such as

spawn, then a

, and finally a points item.

. Multiple

can spawn in one level, varying in type, but I'm not sure how this works so I'll stop talking about it.
Unless you're completing quests, and it won't particularly devastate your course, avoid harmful items like

or the umbrella (You can miss easy levels that would otherwise give you more items, like electriczax pointed out with shortcuts.)
You'll notice that the more quests you complete, the easier the game gets, so the current course I'm setting for myself is killing tuber first, finishing essential quests,
then focusing on points.
If a run isn't going particularly well, remember that you still get practice just by playing, so keep your spirits high and keep fighting to get better used to the game. Given enough time, even newbies like us will kill tuber and reach the pantheon.
Obviously, you probably already know about
Cadomax and the item/quest PDF files from browsing the forum, since you're posting here. If not, these are helpful resources that will be essential in guiding you through ideal PD's, quests, and kill orders to get the giant crystal. Even if points aren't your
primary focus early on, remember that you get lives from high points; the most you'll probably be able to get (same with me) right now are the three lives at 100k, 500k, and 1 million points.
If any pros disagree with anything I've said, feel free to correct me because I want to learn as well. That being said, I hope my advice helps you; I started progressing much faster when I followed these same rules.