Challenge 1: There are a bunch of letters here so you can figure out the answer to the challenges! The flag is: flag{congrats_your_first_challenge} 
Challenge 2: rot13(flag{easy_challenge_right?})
Challenge 3: rot24(flag{how_many_tries_did_this_take})
Challenge 4: atbash(flag{five_down})
Challenge 5: atbash(rot4(flag{double_whammy}))
Challenge 6: hex(flag{this_is_a_boring_one})
Challenge 7: bin(flag{binary_makes_long_codes!})
Challenge 8: hex(bin(flag{this_makes_longer_codes}))
Challenge 9: b64(flag{base64_is_useful})
Challenge 10: b32(flag{I'm_really_bad_with_ideas})