Hey there, and welcome! If you are a supper beginner, you might want to look into the
DAREBEE manual of the website, and it is highly recommended to do the
Foundation program beforehand.
Remember that, whatever your goals are, training is nothing but a third of the effort, more or less. Thankfully, gaining strength is something that can be targeted, so you might want to focus on workouts and programs that involve stressing the core.
Core Strength, for instance, is one of such programs. And if you keep looking into the website, you'll see that a big majority of the abs and core workouts are very short. This is so you can do them at the end of your training session, as a cooldown. Many full body workouts incorporate strength, so this is a way to give an extra stress to that area.
Now, for your last question, if you plan to have cardio and strength in one single session, you'll rather do the strength workout first, and then the cardio. This is to prevent injury. Of course, you can always spread cardio and strength at different times of the day. There is a guide about
training twice a day that walks you through it.
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