Hi, first of congrats for your first changes, however there are some errors you have done while creating these changes, please check and correct them if necessary.

The tracks and platforms on the Hamburg S-Bahn should be tagged as light_rail.

There are also some railway crossings tagged near the station Wedel, which are not possible, as they don't cross any tracks.

The crossing at the Heizkraftwerk should be tagged as disused:railway=level_crossing, as the rail way tracks are also disused.

Abandoned rails shouldn't be tagged, if there is no evidence of them anymore.

Way 1354910319 also seems to not be mapped correctly as it has some really sharp edges and is tagged as layer -1 which would mean that there would be bridges.

The footway over the Mühlenteich doesn't seem to exist anymore.

In addition please separate future edits into more changesets, as it makes it easier to check the work done.