获得 vs 得到 is very similar， they both are getting/obtaining, for example, we can say, 要获得这些材料／要得到这些材料（ physically get/obtain) 他获得了第一名， /他通过努力得到了第一名的好成绩/ 他获得了表扬，/ 他得到别人的称赞 ( accomplishments) 达到 is some sort different, it means achieve (certain degree). 你的汉语达到什么水平了？/ 这么做你可以达到什么目的？ So, 获得 得到 can be you actually received/get something from others, either it is physical objects or accomplishments. while 达到 could be achieve certain degree/results/ Besides, 获得， 得到 we usually used them for positive things, if you get criticism from people, we don’t say 我获得／得到了批评， instead, we say 我受到了批评 Some other synonym of 获得：博得， 赢得

By the way 获得 is more polite than 得到。