I am new Ubuntu and Ask Ubuntu.
I asked a question today concerning how to make a desktop icon in GNOME, but do not know how I get back to the question, to see if anybody has offered a suggestion.
Jacob's answer explains how to search among your posts, which is especially useful if you have many posts and a great tip for us all. However, I think in your particular case, you just don't know your way around the place yet and don't know where to find any of your posts in general. If you only have a few posts, or you want to look at the most recent post, the easiest way is to look in your profile.
Make sure you are on the main site, not meta. Click your username or picture or reputation score in the top bar:
And you will land on the Activity page of your profile:
Look or scroll down and you will see mini lists of your answers and questions with titles. You can organise these lists by newest, most recently active, or highest scoring. In my case, I have written more answers than questions, so answers appear above questions. In your case it will likely be the other way around.
You can click the Questions title to be taken to a more detailed list of your questions.
If the question you are looking for is not there, it may have been deleted. It is hard to find deleted questions, and you may need to ask a mod for help if you need to see your deleted question.
Note that you will receive a notification if anyone comments on or answers your question. The notification will appear as a red square with a number in it (corresponding to the number of messages) on the inbox icon to the right of your reputation and badges counts in the top bar. Unless you have turned off email notifications, you will sooner or later receive an email about such comments and answers too.
In the absence of any supplied information, the following assumes a default Ubuntu Gnome 18.04 desktop. In the title bar at the top right of the screen, left mouse click the section with your picture, reputation, and awards. This brings up your profile. At the top left, select "Activity", and from the list in the middle of the "Activity" screen, Select "Questions", third from the left. Your Questions on the starting (askubuntu) site will be listed.
Note that this answer, along with any other helpful answer or comment, is totally useless in helping the user find their (first) question, since some "helpful" administrator moved everything to another site (Meta, since the question was arguably not about Ubuntu, but how to use the site). Now the user's second question has disappeared!
Oh Meta-Meta where are you when we need you ;^O