those are 2 different questions, people are looking for 2 different things. Neither is a live poker "tell". A live tell is a way you react to the action when it is your turn, or even not your turn, but a distinct action you "put off" that others can detect.
1) Asking you how much you play?
This is basically to figure out 2 things right away, 1) are you lying? if you are lying they will be able to tell right away, usually by how much you talk, what you are doing, how you understand the game, whether or not you get upset over certain situations, if you are confused by certain calls, all kinds of things can tell if you have been playing more than say 2 years or have at least researched the game before playing. I mean no matter how good you naturally are (and im awesome, not to brag, but i have a niche for poker) you are just not going to understand certain calls in certain situations unless you have either read a good bit on poker or have been playing for over 5 years. There are just too many variables and experienced poker players will easily be able to tell if you are lying or not. This is also a way to tell how good you are at poker or just your general experience. They will generally ask this after they have seen you make either a very good or very bad decision, wondering if you did this based on good variables and reads or if you did this based on instinct and natural ability. Generally a bad decision will give them their answer quickly. I ask this question all the time. Remember, poker is a game of tons of variables and different situations, all the information you can gather will come in to play, from their love life, to the name of their dog. Believe me!
2) Asking how many chips you have behind. This is usually to figure out what they can do with their chips and what moves they can make in the future. Sometimes, this is done as a reason to find a tell, but more than likely when you play w someone that asks this question they are doing it to figure out what kind of math is going on. Can i 3 bet here and fold and still be ok? If i do 3 bet this gentleman or ladie am i going to be pot committed now? How many chips will this person have left w the blinds at this level and do i think they are going to fold? These are all possible questions to ask yourself when someone asks this question. Very often, this is a question also done in posturing, usually done when you ( the person being asked ) has made a check-raise or 3 bet and the person knows they have no chance of 4 betting or calling the check-raise, They will simply ask "how many chips do you have behind?" in an effort to make it seem like they were making a respectable play, when really they were playing off of weakness entirely. They know they have no chance of calling or making a play here, unless they have priced themselves too deep, in which case the math comes into play. Its strictly a move to throw you off and make you think they are playing respectable poker and honest good cards, when really they were just wondering how far they could push you around. Generally, and definitely with more advanced or professional players, if they are playing math as a part of their general strategy (almost everyone is) they know exactly how many chips you have (or a good ball park figure). They have no reason to ask you this question because they know what you started with, how many blinds you have, and your respectable fraction to the pot size, BELIEVE ME! These things all go through a persons head within 20 seconds of every hand, There is plenty to think about.
Neither one of these things are really looking for a "tell". I mean the 2nd one could see if you are a bit nervous about saying how many chips you have behind, (thats generally done more in a cash game than in a tournament) But thats just to see if you are playing w scared money. Which you either are or you arent, and its not that hard to figure out which one you are doing. If you are in a tournament there are plenty of easy tells to find. And FALSE TELLS. its all how deep you think the person can play and how much they can incorporate their math skills, with their acting skills, and their natural ability to be nervous. This is why so many professionals stay so still and dont make any moves at all, its just easier to give off nothing than to persuade someone with your acting skills. you have to be a "salesman" a "good actor" to persuade calls and in turn not give off any information about yourself, or at the very least throw people off. I wont get into every single tell, but there are tons, twitches, freezing, playing w chips, the way their eyes go, the way they talk, whether they talk or not, everything they do from the time they look at their cards til the time they are done the hand could be a tell. For me, i practice false tells the most, but they only work against the best players, so i have to first identify, then get a hand, then trap a person, then throw them off, so all those variables to fall into place are hard to get, but they happen sometimes, and thats just acting like you are nervous or giving off an obvious tell in order to persuade the person to think you actually have nothing. "sandbagging" could be another term used if you have a great hand.
As far as tells go, those are the reasons for asking those particular questions, If you have any others i'll be happy to go into more detail on them, but there are a ton of common questions poker players ask. It all leads to the same thing. To get more information to make better decisions later down the road, even if they seem like they are just being friendly. And all of us like to be friendly, just like chess make sure you know what they are thinking about you and use that information to your strengths not theirs, just dont let them know you know what they are thinking. lol if that makes sense. Good luck in future events, and if you are less experienced and want to give yourself an edge, sit down, shut up, and dont say anything to anyone. Let the cards do all the talking, but never show. Good luck.