Don’t understand these written instructions

[Desireeleo]

So I bought a pattern off Etsy. 
 

number 2 just says increase, doesn’t have a number 

3: inc, sc2 (24)

4: inc , sc3 (30)

I don’t understand steps 2-4 like what does sc # mean 

[bgs]

When you a purchase a pattern the person that sold it to you should be available to answer your questions as they profited from the sale.  This pattern is not written using the conventionally accepted standards for crochet patterns but is more of a shorthand----much faster to write but instructions not always clear to follow.  This might help.

inc means make 2 stitches into 1 stitch (if supposed to make more than 2 it should have specified)

2: inc

Make 2 sc into each stitch of previous round. 

3: inc, sc2 (24)

Make 2sc into first stitch of previous round, make one sc into each of the next two stitches.  You repeat this sequence to end of your round and should have a total of 24 stitches in that round.  Numbers in (  ) are stitch counts.

4: inc , sc3 (30)

Make 2sc into first stitch of previous round, make one sc into each of the next three stitches.  You repeat this sequence to end of your round and should have a total of 30 stitches in that round. 

Sometimes you have to guess and make a few attempts until the numbers match up.  From what you have given and looking at the numbers I can surmise you started with 9 sc in round 1 and that the stitch count for round 2 was 18.