Fish emulsion kinda stinks and is slow to release its nutrients. It's okay for long-term building of soil fertility, but for container plants in storebought potting mix, I'd recommend sticking with soluble fertilizer like Miracle-Gro or Peter's.
For vegetative growth, I'd constant feed (meaning use this rate at every watering) a balanced fertilizer (20-20-20, etc.) at ~200 ppm nitrogen (so dilute it to that range, then add to plants). An easy way to do this is by mixing a stock 16x solution and using a relatively inexpensive Siphonex or HoseOn 16:1 injector that attaches to the hose at the faucet.
For flowering, I'd switch to a 10-30-20 or 10-52-20 (or some similar formulation) at the same concentration.
That's just my recommendation. YMMV.
When you water, do so until the soil is saturated and water drains from the bottom of the pot. This will help leech excess salts from the pot. Then, don't water again until the soil is almost dry - stick your finger in a couple of inches and feel it. In time, you'll learn to tell when to water without feeling it every time.
If your plants appear to have nutrient deficiencies, you should probably check your soil pH. Different elements are more or less available, depending on the soil pH. Potting mix tends to run on the acidic side, and fertilizers can increase that acidity over time.