I am of the view that healthy soil produces healthy plants and so don't fertilize per se. I add a lot of organic matter and turn it into the entire bed before I plant anything. Once a bed has plants in it, I top dress with compost and add a layer of hardwood chips to the surface every few years. This adds nutrients slowly as the organic matter breaks down, keeps the weeds down, and helps keep moisture even in the beds. The worms and other soil critters mix the soil as they eat and digest the organic matter, and I find I don't spend much time weeding mulched beds.

Keep an eye on soil moisture and water appropriately for the plants you have, which in my area most years is never since we usually get regular rain. Some plants like it drier and some damper, so know what your particular plants like. When you do water, it should be long and slow to let the water sink in deeply and encourage deeper roots. Hand held watering is almost never adequate, both because some plants don't appreciate wet leaves and splashing can spread disease, but also because watering tends not to be even or enough when done by hand. If you are in an area that needs watering most years, you might want to invest in drip irrigation which uses the water more efficiently. New plants will need regular water either from rain or from you until they develop enough roots. For most plants this is a good chunk (if not all) of their first growing season.

You might want to put zone and location information after your name in all your posts as some advice will vary according to where you are. To do this

Go to Your Houzz in upper right of every page, click Edit Profile, and on the left side click advanced settings. Well down the advanced settings page is a blank labeled Climate Zone for Garden Forums along with a link to find your zone.

Then return to the top of the page and click Done Editing.