some pointers: just invite to connect at least current colleagues, just to get ball rolling.
also: even if you don’t have much to add, describe in more detail what you have already done in that pisition, so recruiters/hiring managers will have better understanding where you are currently.
also also: linkedin profile has section “skills” where you select what you do. don’t skip that section, it is used in filters while searching potential candidates.
at your stage it would be massively helpful to have some kind of certifications if relevant (just as an example: symfony developer certificate, if you do PHP development), and so on.
and don’t get upset about those massive salaries mentioned on HN- the reason they are mentioned IS because those are big salaries. take a look at avg salaries in industry of your location and you will see real situation.