The AfD is still looking for people who can spend some time before the election to placard posters, distribute flyers and stuff into mailboxes, man info booths (together with experienced guys, of course), help prepare locations for speeches, look for posters being damaged/stolen, go to local meetups to discuss plans/ideas etc. >afd.de/zeit-spenden
Also if not even more important apply as Wahlhelfer to prevent election fraud. (Check your local deadlines at your town hall) You get even some money from the government for this, between 60-90€
Or if you don't want to spend the entire election day at the polling station, please go there as Wahlbeobachter. Every citizen got the right to be there when they count the votes! Just go there a few minutes before 6pm on election day. You don't need to do anything else.