what do you think is the best strategy for a good low level poker tournament
Other than the course I recommended, I'd say it depends on your skill level. Are you a newer player yourself (and why you are in the lower levels) or are you more experienced and simply happen to be playing the lower levels?
If you are also newer yourself, then I recommend playing a TAG strategy and playing better cards preflop. If you are the most experienced player there, then I recommend loosening up to a LAG strategy and seeing more Flops against players you might be able to better exploit post-flop.
Just a generic opinion though; not saying these styles are universal. In fact, some players simply can't play more than their natural style, so you might need to experiment and see what works for you. The reason I recommend a TAG style at first is to give you some "experience" and exposure without putting yourself in as many difficult decisions. A TAG player will put themselves at risk less often (by playing fewer hands preflop) and will usually have a range advantage throughout the hand (because they were more selective preflop). Once you gain more playing experience and learning subtleties, then you can optionally loosen up to playing more cards in more spots and using more advanced strategies.