You can check mlpmerch and/or strawberryreef online. Good luck but feel free to ask questions
Just a note, but I wouldn't recommend either of the above sites for ID re: G1 ponies (Strawberry Reef is ok for G3, MLPMerch for G4). Both have mistakes and MLPMerch isn't really an ID site anyway for the earlier gens, it's a cataloguing site. Strawberry Reef is out of date as it was abandoned several years ago and so doesn't get corrected.
If you want to use a mainstream site, the MLP Wiki is better than the above two. No site is perfect, but Wiki is at least updated and generally more accurate for G1.