How to cook Lo Mein?
OK I can read Chinese and let me tell you the answer: the noodles you bought are made by eggs. They're not made by rice. (FYI, there are TWO kinds noodles called "Rice Noodles", they are actually made by rice. The two kinds varies in thickness).

You can first make soup noodles to grasp the texture of the noodles you bought. Try undercook and overcook a bit, see if you can find the sweet spot you want.

Now, to go with other ingredients, here's how Chinese "fried noodles" are made:


Prepare a pot of boiled water (must be boiling at 100C, not just hot)
Add a bit of salt into the water. This helps taste and prevents the noodles absorbing too much water.
Add a bit of oil into the water. This prevents the noodles from sticking together later in the process
Put the noodles in and cook them for 30s to 1 min. Never (very important!) cook them for more than a min.
Take out the noodles. They should be undercooked now, which is good. Use a scissor to cut the noodles, otherwise you'll have very long noodles later in the process. There is no need to rinse them using cold water if you use this method.
You can turn off the heat to the water pot now. But don't throw it away.
Add oil to a hot pan, cook the spices (e.g. onion, green onion, whatever you use)
Cook the meat ingredients in the pan.
Add a slight amount water from the pot (which has salt and oil in it) to the pan. Also add sugar, soy-sauce, etc. for final adjustment of taste.
Now put the noodles into the pan. If done correctly, all the water (should look like soup by now) should be absorbed into the noodles right away.
Cook the noodles a bit.
When the noodles are around 80~90% done, add the vegetables.
When the vegetables are done the noodles should be done as well. Finish!


As for Lo Mein, it's not a kind of noodles, rather a style of cooking noodles. When making "Lo Mein", the noodles are only cooked by hot soup. A "Lo Mein" dish is where the noodles are cooked by a minimal amount of water. It's like serving soup noodles but without the soup. The procedures are largely same as above, except the noodles are put into the pan at a later stage and only briefly fried, or not fried at all. I personally consider "Lo Mein" a more difficult dish than "fried noodles" (aka "Chow Mein").