To create a MUT team, all you need to do is to go through the tutorial and introduction of Madden Ultimate Team;
Once you have completed the opening introduction of the game, you will be brought to the main menu. From here, select Ultimate Team and go through the requirements that are given to you, which are
View Lineup,
Collect NFL Stars,
Upgrade Your Team, and
Play Game. Completing these four objectives (which are very easy to do and follow) will net you the achievement.
While doing the objective of
Play Game, you can also get the achievement of completing a Solo MUT challenge of scoring a touchdown.
If you have any suggestions or questions, please leave it in the comments and not just downvote. Hope I helped ;)