Well you said it yourself - you're just starting!
One important thing when starting out is scope. Don't be too ambitious with your first project as you'll hit a brick wall at some point and think "this is far too difficult".
As for a side scroller.. It's a good choice as they aren't too difficult. Lighting and particles, save those for later. Physics? You could use box2D (http://box2d.org/) as that's quite a popular choice to avoid all that nasty mathematics ;)
I'm not sure why you're thinking about lighting when (I assume) you're just doing a beginner 2D game? Save the advanced concepts like particle systems and stuff for a rainy day IMO!
EDIT: By all means, do the physics yourself. Check out Axis-Aligned Bounding Boxes (AABB) - plenty of theory on those and plenty of stuff that's relevant to games. It's a pretty soft introduction to the mathematics of games