Question about Limit Orders and Bid & Ask Prices

Hey guys, I have a question about limit orders and bid & ask prices. I want to start trading but I don't want to find myself in a position where market orders screw me up, so for example if I place a market buy and it executes at a much higher price than the market price or vice versa with a market sell. Now I know that you can use Limit Orders so you can buy or sell at a specific price or better. But my question is, at what price do you set a limit order if you want it to execute right away, while avoiding an execution at a higher/lower price. I'm not sure if I'm explaining myself well, but I kind of want a limit order that executes right away and the difference between that and a market order being that the market order may execute at a surprising price to me, while the limit order won't.

Example: Last: $ 124.58 Bid: $124.53 Ask. $124.60

My common sense tells me that if I want a limit order that executes right away at the best possible price right now, I should put in the order at the ask price which is $124.60. Am I right?

I think this also brings up another question that I have. Why is the last price different than the ask price? Is it because the ask price at the moment of the last trading price was that and has changed since?

I know this is too long and a little confusing, but if anyone can help me here I would really appreciate it. Thanks

Edit: Typo

Submitted March 29, 2017 at 02:14AM by ConorMcGregor15 http://ift.tt/2nu1bco