Question

I know a users name but can't figure out how to locate them to send a private message.

Answer 1

If you know their Wikitree ID, go to your own profile.  The end of the URL has your Wikitree ID. Just change that part to the other persons ID and load it, which should land you on their profile.  In the orange line In the box under the Birth and death info, it has 'send private message', which you use.

If you have a question about a profile that the person is PM on, it is better to find the same link on the profile.  Selecting the 'send private message' next to a PM name will send a message to the PM and also include that profile ID in the subject line of the message.

Answer 2

At the top of your page, you can search for their name (as you would for any ancestor)

Answer 3

If you can find them in a G2g post or on a comment on a profile, you can also click their name it will take you to which ever page they have as their start page.  Now if they chose their g2g profile as their start page you won't see their profile infos, you will only see their g2g level, and g2g infos & badges as you scroll down the page, you'll know its the g2g by the green box that tells their Score/ Title/ Level/ ie: g2g pilot,  etc.. if you end up on this page, just click their wikitree profile .....Name-0000  at the top next to their picture.

If you can't find them in a comment or g2g post (which you can search g2g using the search box and their full name or their last name, id, etc.. you also have the options that Linda and Dennis gave you.. Another thing you can try is just do a ggl search using... wikitree, firstname, last name this will usually allow you to find them fairly quickly as well.