I always find shiurim that translate well the Gemara into English but I have difficulty with Rashi. Where can I find a translation of Rashi on Gemara?
The Mercava is your best bet for online; most of the Rashi is translated to English, it depends on the masechta. Just click on the line of Rashi and you'll see an interlinear translation at the bottom of the page. It's a great resource; I use it all the time. Also the text of the Gemara is translated too.
Of course, if you're looking for Rashi in print I'd suggest getting an ArtScroll Shas; it's not exactly translated, but the translation weaves in Rashi's commentary and also the footnotes on the bottom more or less bring Rashi's point, as mentioned in the comments to the OP.
Of course there's always doing it the old-fashioned (and much more difficult) way, which is sitting in front of a classic Shas with a Jastrow's dictionary nearby...
I think the best current (and certainly even more so in the near future) resource for English translations of traditional texts can be found on sefaria. Not all of Rashi has yet been translated, but here is an example from the first daf of Berachot: https://www.sefaria.org/Rashi_on_Berakhot.2a.1?lang=bi