AS long as you never plan to go above a GTX 1050 Ti, you won't need much beyond a 350W PSU. But I suspect you will be wanting to upgrade in the future, so look into a good quality 500W or better.
https://www.newegg.com/Product/ProductList.aspx?Submit=ENE&IsNodeId=1&N=100007657%2050001697%20600479294