Need advice about tuning up my 986

[Lucky]

If I were you... I'd do nothing!

Do a few DEs. Your car is very capable in stock form and will more than exceed your abilities (to start, anyway).

It may turn out that you don't like track driving. If so, your unmodified car will still be in its perfect, factory street trim.

If, after a few DEs, the bug has really bitten you, then you have a multi-year slipperly slope in front of you that starts with innocent mods to your car which over time make your car far less fun on the street (but a blast on track) and eventually you end up with a big pickup truck and a trailer to shuttle your track beast around.

If you really get that serious, the Boxster may not be the best platform. It all depends on the group you run with and your own goals. By me, our PCA run groups are full of 996TTs, GT3s, and Cup cars... to say the least a Boxster can't keep up. It can get frustrating in a slow car surrounded by fast ones. If you have a similar situation in your region, then you may want to join the arms race once you get accomplished at driving a mostly stock Boxster.

Food for thought.