Try looking at the 12 principles of animations.
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After that, understand the tools for animation in Blender, searching for keywords such as Shapekeys, DOPE sheet, NLA (Non-linear animation) then moving onto a more advance topic such as Drivers.
Something to consider is understanding the key poses that make up your animations. Think broad then work your way down to the finer details of the animation. For example, let's say you're doing a doggy style animation. The 3 main poses would be,
Note that when I say 1st, 2nd ect keyframe, this doesn't mean the 1st frame in the timeline.
1st Keyframe = Initial pose
2nd Keyframe = 2nd pose
3rd Keyframe = Copy of 1st keyframe + an empty at the end.
Now this can get a bit tricky if you have like a "pre-staging" (don't know the technical term) animation. Something like the man is standing holding his penis and walks up to insert, you'll have to figure out what frame is the initial "main" pose and adjust accordingly, not just in Blender, but the game engine of choice.
It would look something like this (imagine the timeline this time) let's say your animation is 30 frames long,
Keyframe 1 = Initial pose | frame 15 = 2nd pose | Frame 30 = Initial pose + 1
for a total of 31 frames, the reason behind having that empty frame at the end is so that the loop doesn't look like it skipped or a jump for lack of words. Once you have establish those 3 main keyframes, start filling out the in-betweens, i.e from frame 2 to 14 would be the small details such as breast bounces, body movements, facial expression ect. copy or create new ones for frames 16 to 29.
At the end of this, depending on how you want to implement them, either as a mp4 file or sequences of images (the images will render based on the keyframes you have.) There's also a setting to only render every X amount of frames, but doing it this way you'll have to do some calculations in whatever game engine you're use to match whatever total frames you had setup in Blender.
As far as getting errors with morphs, don't quote me, but I believe the Daz3d to Blender plug-in doesn't support morphs targets that well. You're probably better off using Diffeomorphic plug-in.
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Do take the time to read the documentation, as I'm not too familiar with the process.
If any of this sounds confusing let me know and I'll try to clear them up.