Good advice above. And when you buy a harmonica stay with it until you can play a good tune before you spend money on other types of harmonica. Some beginners keep buying , thinking a different harp will be better. Learn to play one then going to others will be much easier.
And at first it will be difficult to get a tune out. You Need to know the basics before getting to songs. You’ll need to practice getting to move up and down getting just one note sounding. You’ll need to squeeze your lips like drinking through a straw or cover 3 or 4 holes with the tongue and blow from the right side of the tongue and get single notes. Once you can do this then practice moving, skipping over some holes to get another clear note. If need be practice this for as long as it takes. There is no easy way, just practice. It can be done. Then and only then you are ready to start playing songs.