I'm an amateur player and want to learn a couple openings for black. I want to have a response for d4 and e4. I want one for each and hopefully one that is relatively straight forward (unlike Indian defense as I understand). It would be great if they were slightly obscure and therefore unknown to my opponents. As white I'm basically going to try and play Scotch opening (and maybe later some other e4 openings) every time.
I agree with @CognisMantis regarding meeting 1. d4 with the Dutch defence.
I would advise playing the Scandinavian against 1. e4 (1. e4 d5), as it is 'obscure' in the sense that Black brings the Queen out early (1. e4 d5 2. exd5 Qxd5), but it is quite playable due to Black's pawn structure tends to be quite solid (similar to the Caro-Kann) making sure White is unable to exploit the slight lead in development.
Before trying the line out, check out the opening video by Dereque Kelley first.
(As a piece of advice in general, if you are new to an opening, see a YouTube video discussing the major themes. This way you can get a feel for the opening)
As noted in another answer here, the Leningrad Dutch may be an interesting option to look for as black against 1.d4.
Against 1.e4, you may want to try Alekhine's defense. It's actually quite dangerous for any white player who doesn't know how to reply to it properly. As far as I know, it's not a common opening, but I have noticed that I'm facing way more Alekhine players nowadays than I did in the past.
It all depends on your playing style if the Alekhine's defense suits you or not though.
Since you want obscure openings, I would advise the Dutch defense against 1.d4 and the French defense for 1.e4. The Dutch is played less than Indians, queen pawn, Nimzo, Gruenfield, Slav..., thus your opponents won't know anything about it but you will. The Leningrad Dutch and Stonewall defense are played time to time. Nakamura has played the Leningrad Dutch numerous times, Magnus, Levon, Anand, etc have used the Dutch from time to time. I recommend the French because I think it is much easier to learn than 1.e5, which falls to a lot of traps and 1.c5, which is of course not obscure and has a lot of theory. Unfortunately, people can go into a very drawish line in the exchange French. You might want to consider Owen's defense 1... b6.