Plant connaisseurs, I just bought some liquid plant food (Miracle Grow) and I need some help, please?

I have just started picking up a few small indoor plants for my apartment. The plan is to get some bigger ones in the next few weeks. So far, I have a few African Violets, an Angel wing begonia, and the cutest lil’ Shamrock plant that you eva’ did see (I love how it ‘goes to sleep at night”). Not sure if some of these plants even need the plant food. Do you all have any advice, tips or things that I should know (do’s/don’ts) when it comes to plant food?