The 'year to date' total is always there, over to the right at the top of your selling page.
To be honest, if you want to know your obligations to HMRC, I would recommend looking at the gov.uk/HMRC websites.
Rules for private sellers have not changed. Unless you are buying to sell and trading, you are unlikely to have any tax liability but there is lots of useful information out there. Just use reliable, official sources.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)
