We can use the verbs begin and start to mean the same thing but begin is more formal than start. Begin is an irregular verb. Its past simple form is began and its -ed form is begun: When did you begin learning English? The meeting didn’t start until 9 pm. We use start, but not begin, to talk about machines: Press this button to start the printer. Not: …to begin the printer. The lawnmower won’t start. (this means that it doesn’t work) Not: The lawnmower won’t begin. Start, but not begin, is used to talk about creating a new business: She started a new restaurant and it’s been going really well. Not: She began a new restaurant …

They are not always interchangeable. You can start some things but not begin them--"start" has more agency associated with it. For example, you can start a car and you can start a fire, but you can't begin a car (well, I suppose you could but it would mean something else).

There's not much of a difference between the two. You can pretty much use either one in any situation, so I would just think of them as having the same meaning.

Start(the verb) and begin have the same meaning. There are some differences in when we commonly use them but the meaning is the same with either. Sometimes "begin" sounds more formal than "start". "Start" can also be a noun (The start).