pH should be in the 7's. Anywhere in the 7's is fine. If you're using liquid chlorine to chlorinate, pH will rise over time as your pool off-gasses CO2, and you'll add acid to bring it down - take it back to 7.2 when it hits around 8.0. TA is mostly just a number you need to know so that you know how much acid to add - as you add acid it will lower, and that usually slows the rise of pH so you're adding acid less frequently as you go. You want the TA to be at least 50 to ensure you have some buffering and don't have an unexpected pH crash. There are some reasons to worry about high TA, but they're not super common, as it'll just reduce over time with the acid additions anyway.