

It’s important to recognize an individual can not move a mountain, so it’s important not to get discouraged because you do not see tangible progress nationally. All politics is a grinding trench fight to wait for an opportunity to enact laws.
With that said, the very minimum thing any citizen should do is vote. Vote in local election, vote in federal election, vote in EU election.
Next is attend your local party meeting of your preference. Just showing up and listening shows that there is interest to the politicians. You have opportunity to meet like minded people which is important for networking.
Why do you make it sound like showing up for half a day and casting a vote is some ultimate sacrifice. That is the minimum duty of a citizen.