Consistency is key, and that comes with practice You'll need to run rod after rod after rod after rod after rod... It's not something you pick up in a couple of passes.
Looks like you were moving far too fast at the bottom. Moving too fast is generally the problem with any stick welding.
Stack some beads scribe or mark some lines to follow if you have to... once you can make them relatively straight, start stacking them half on top of each other... This makes more sense than running individual beads on a surface, since it's more like trying to fill a proper joint.
Dunk the practice piece in water to cool it down after a few passes, or everything will get too hot and runny.
It's a technique that only comes with practise - lots of it.
Good surface preparation and if you're in a comfortable position try and support the rod with your other hand; progress will be steadier and keeping the arc in the root will be easier too. As the puddle forms move the rod slightly up maintaining the arc; as the puddle 'freezes' return the rod and lay another weld over the leading edge and so on.
It literally took me weeks to learn this and I had a tutor who was a trade welder at the top of his profession. My first efforts had more slag in them than weld metal.
I got there in the end, so you surely will.
As Munkul said practice will develop consistency and quality. I like the idea of stacking beads (I'm assuming that's like a pad weld as pictured below?)
Try something on the lines in the photo initially. Once you're more proficient, start practising weaves. After that fillet welds and then vee prepped butt welds to develop your weaving technique further.
Make sure that you're using electrodes designed for vertical up work, this will make things better; they are expensive, but I've always used either 'vodex' or 'fincord M' there will be other manufacturers, esab etc, find the one that you are happy with:
Do not be afraid to use enough amps, I ALWAYS use as many as I can: YOU are controlling the weld pool, not the pool controlling you:
Keep your arc short
Keep the weld bead narrow, just wide enough to allow one side to 'freeze'
I'm assuming that if you're now trying to positional MMA weld, you're able to down hand, and therefore able to recognise what is weld metal or slag; WATCH what is happening, watch the weld pool, watch the parent plate;
At some point, it will gel, keep at it, you will get there!