The first strike in a round is granted to the team that has the highest first strike value, which is indicated by the blue numbers. When you first start a match, look at your enemy's team to determine which of their units has blue numbers. Focus on those units first using the Targeting ability. If you can to take out all of their units with blue numbers, the enemy will never be able to go first. Focus your attacks and take down your enemy one by one. With high enough rolls and the Targeting ability, you can take down one of your enemy's units with each turn. If you do not use Targeting, your units will randomly choose their targets, spreading their damage out.
Team layout
With your starting units, the lighter ones have less HP but have more blue attacks and lower damage values. The heavier units have more HP but usually have at maximum one blue attack and higher damage values. Try to have a balance between the two types to get chances to strike first as well as enough damage to follow through. Some units have red attack bars which indicate that they have a special ability. This can be a armor increasing shield, the ability to attack multiple times, etc. These special abilities will only activate if you land on the red space during your spin. The Respin ability is useful when you are trying to use those types of units.