Circle the dot

I’m trying to make a game like circle the dot i just don’t now where to start
https://itunes.apple.com/us/app/circle-the-dot/id905410455?mt=8

@Dantheman2001 Start with this. Just tap a square to change it’s color.

displayMode(FULLSCREEN)

function setup()
w1=WIDTH    -- save starting width
h1=HEIGHT   -- save starting height
size=30 -- size of squares
w=w1/size-1  -- number of horizontal squares
h=h1/size-2 -- number of vertical squares
colr=color(255,0,0)
tab={}  -- table of touched squares
col={}  -- color of touched square
end

function draw()
background(40,40,50)
for x=0,w do    -- loop for horizontal squares
for y=0,h do    -- loop for vertical squares
for a,b in pairs(tab) do    -- loop thru touched table
if x==b.x and y==b.y then   -- does square match touched table
fill(col[a])   -- if yes, then color it
end
end
rect(x*size+10,y*size+10,size,size) -- draw square
end
end
end

function touched(t)
if t.state==BEGAN then  -- screen was touched
x1=math.floor((t.x-10)/size)    -- calculate x square position
y1=math.floor((t.y-10)/size)    -- calculate y square position
for a,b in pairs(tab) do    -- loop thru touched table
if b.x==x1 and b.y==y1 then -- check if square was touched
table.remove(tab,a) -- remove it from the table
table.remove(col,a) -- remove it from the table
return
end
end
table.insert(tab,vec2(x1,y1))   -- square touched, add to table
table.insert(col,colr)  -- square touched, add color to table
end
end

@dave1707 thx for the table