Hi Sarra,
You have received some good advice here, but I will offer my own perspective.
1. I would recommend uploading to all three sites that have been mentioned - My Heritage (which you have done), FTDNA and Gedmatch. Everyone's experience is different, but I have found something useful at all four sites. Ancestry has the biggest database by far, but it is the hardest to work with. FTDNA and Gedmatch have less people but very good tools. If a match looks interesting, I often ask them if they are willing to upload, generally to Gedmatch, so I can compare them with other matches (see below). Gedmatch also allows me to easily send comparison tables to send to people I'm discussing with.
2. Two of the features I find most useful are "In common with" and a chromosome browser, both of which provide ways to see if different ones of my matches also match each other. Then if I know that a match is (say) from my maternal grandfather's family (e.g. a relative has tested), then people who match us both are likely matching on that side of my family - if there is a significant match all on the same chromosome segment, known as triangulation, then a joint common ancestor is virtually certain. If you are researching a particular branch of your family, this information can help define which matches to follow up further.
3. Whenever I contact someone on Ancestry, I ask them to invite me to view their tree. That way I can see it whether I am subscribed to Ancestry at the time, or not.
