That depends on what kind of tea you want to try, but I'll give some examples
Japanese teas can for some be a challange because of their seaweed and grassy aromas so good new begginers teas in that catagory is gen mai cha, hojicha and kukicha.
When it comes to finer black teas, teas like Darjeeling and Yi mei ren most people like (everyone I have served Yi mei ren to have liked it).
When it comes to Pu-erh it's important not to buy the cheapest one and to remember to "wash" it.
When it comes to smoked tea Lapsang Souchong can be a bit too smokey for some people så there it can be good to try "Russian caravan" or other plain blach and lapsang pu-erh blends. If you cant find that, try mixing it yourself.
If you want to try teas of finer quality and you aren't ready to try unflavored teas, try a jasmine tea of a little higher quality, ginseng oolong or gen mai cha.
If you want to try oolong and like licorice you can try ginseng oolong
If you want to try plain green tea bai sha lu can work if you brew it the correct way (no more than 30 sek)