Caulking is a relatively simple task, but how it looks and how it adheres is another subject.
First, most people cut the tube end at a too large of an angle. The angle should be around 30 to 45 degrees depending on your style, but the size of the hole should fit the requirement. Sounds like the opening is too large in your situation.
Secondly, after you have laid about a yard of caulk, dip you finger in water or better still alcohol and run it down gently the length of the caulked area. you want a nice smooth transition between the wall and floor.
When you watch your wife ice a cake, she dips the kife in water to make the icing do smooth things and it does not stick to the knife. This is your goal.
If you caulk too far and then go back with the smoothing process, the caulk will have developed a glazed finish and much harder to mold.
Remember, there are now about 25 different caulks for as many projects. Silicon is good for bathtubs and bathroom caulking. it is flexible and sheds water, but you can not paint over silicon.
for painting purposes, you need a mixture of silicon and latex, the tube will plainly state paintable.
They have just released for the market a silicon caulk that will take paint, I have not tried it.