how do i pick a random mesh and textureid from table?

One really simple way to do this is to use a numeric for loop:

local mesh = {55, 33, 16, 4}
local texture = {22, 6, 11, 5}
local Storage = {} -- Make a table to store patterns
for i = 1, #mesh do -- This doesn't really matter because I'm assuming that your tables are going to have equal lengths anyway
	table.insert(Storage, mesh[i])
	table.insert(Storage, texture[i])
end

If you otherwise want it to be completely randomized, I would use math.random():

local mesh = {55, 33, 16, 4}
local texture = {22, 6, 11, 5}
local Storage = {} -- Make a table to store randomized patterns
local ChosenMesh = mesh[math.random(1, #mesh)]
local ChosenTexture = texture[math.random(1, #texture)]
table.insert(Storage, ChosenMesh)
table.insert(Storage, ChosenTexture)

Using a for loop to get the values by index places them in a table so that for every 2 values in a table the pattern is mesh[i] followed by texture[i]. Using math.random() randomly selects them from the tables and stores them in random patterns.