A lot of good advice on this thread -- my 2 cents, although this is a forum centered around indicators, please be sure to understand the underlying price action that moves these indicators first. Price action is what moves every indicator you use, not the other way around, and getting too "indicator happy" too quickly will inevitably backfire in my opinion.
@w4bmastah gave some good examples of his preference, whereas my preferred way to navigate price action is through supply and demand zones:
this was an example of zones working out well from around 2 weeks ago; you should be able to see multiple points of entry based on rejection of these zones. I saw that you said you don't like lots of stuff on your screen, but I just turn my transparency of the rectangles up high. If you'd like to learn, I learned a ton from Carmine Rosato on youtube:
https://www.youtube.com/channel/UC9KV4pshtiKoQF_IanKiT_w
I also trade SPY/SPX exclusively, with a combination of the 3min and 15min time frames on my screen. I use the GoodAs indicator, the SwingArms indicator, the B4 breakouts and the QQE mod -- as well as some indicators I made myself, but the underlying foundation of my trading is based on price action, as should always be the case.
My chart:
http://tos.mx/lbTNVAW there's probably more on it than you'd like but you're welcome to look at each study involved. The SwingArms are currently hidden on the chart, but it's a helpful study if you like ATR retracements