There are many ways and times to enter the market. You can just pick a time frame and trade with that chart. Or you can start by finding the trend and using that as the direction of the trade then enter when the price is at a good spot for you. Or you could use one time frame in conjunction with another time frame to help you fine-tune and time your entry and exits points.
It is always best to trade in the direction of the trend. If you are a position trader then the day and week time frames will be your best bet to find the trend. If you are a swing trader just a few days in the market then the four-hour seems to be one of the best time frames to get a good direction for the trend, but still keep an eye on the day chart.
A position trader has to acquire a lot of patience over time to gain the experience to be able to stay in a trade when it is going against them by large amounts and know that it is just a retracement on a larger time frame. A new trader also has to work their way up to be a swing trader so they can leave a trade on over night or over the weekend. It is easier to stay in a trade when you are trading in the direction of the trend. If you time the entry right then you will be getting in the market at a very good time, which makes it easier to stay in.
So how do you time an entry? The best way is go to a larger time frame and get the direction of the trend. There are several indicators that can help you determine the direction of the trend. Once you have found the direction of the trend then you can move on to a smaller time frame to catch the trade just as it is going in the direction of the overall trend. The smaller time frames will oscillate up and down, in and out of the direction the trend is going. When the signals say that it is heading in the right direction, that is a good time to get in. You can spend a lot of time going from the 4-hour to the 1-hour to the 30-minute to the 15-minute charts looking for the right timing. All you need to do is figure out which time frame is easiest to read then use that as your entry time frame. This may change from trade to trade. Another way I have heard of is to look at the 4 hour chart then go to the 30-minute chart to get your entry signal. Once you get a signal on the 30-minute chart then look at the 15-minute to confirm your entry.
In summary, start with larger time frames then move to smaller time frames to find the best entry signal for that trade.