Type of line for trail in the wood (park).

There is some variation on this depending on local mapping customs.

If the trail is exclusively for the use of one type of access or even primarily for one type, then you could use highway=cycleway (exclusively or mostly bicycles), highway=footway (exclusively or mostly foot traffic) or highway=bridleway (exclusively or mostly horses). In my area most trails are open for hiking, mountain biking and often equestrian use. My reading of the wiki indicates that these general use trails should be highway=path.

From my point of view when rendering maps, it is very useful to add some other tags to help make clear the type of trail. These additional tags may include surface=*, sac_scale=*, trail_visibility=*, foot=yes|no, bicycle=yes|no|designated, horse=yes|no, wheelchair=yes|no|designated, and possibly others

I can’t say about other people attempting to render maps, but I consider a hiking trail to be quite different from a walkway in a city park and since mappers can and will use highway=footway or highway=path for each. So adding some other tags are useful in figuring out how to render the trail. For example a way tagged with highway=path, surface=unpaved, trail_visibility=good is likely a hiking trail. But a highway=path, surface=concrete, wheelchair=yes is likely what in my local dialect would be called a “sidewalk” (even if it isn’t along side a road).

So I guess my final advice is to look to see what other mappers in your area have decided to do and follow their example. But please add additional descriptive tags to help clarify what is there.