My advice is to write a ton of songs so that you can throw away a lot of songs, your best songs will rise to the top. Sometimes it is hard to cut songs, but artists will rarely write good songs every single time. Also, don't be afraid to get some honest feedback from people you trust, this can help you lift the blinders on what is working an what isn't, but you're the boss, so your opinion matters to, so don't let anyone walk all over you.
Especially for your first release I'd go with an EP (maybe 5 songs), like others have suggested.
I prefer to write concept albums over compilation albums, where I plan out a theme or musical idea that shows up in every song. On my newest album I wrote and created a comic book and used the story from that as a guide for the music I was writing.
Since you already have songs that you want on an album, your album will most likely be a compilation-style album, so consider what I've written below about album flow.
As far as my personal preference on album flow, I generally do this:
(1) Start with a short energetic song that throws people into the album, and leaves them wanting more.
(2) Start to mellow out a bit until your middle song is the least exciting song on the album (but still well written).
(3) Build the album back to an exciting ending and possibly place your longest song at the end.
I don't write all albums this way, but I find myself doing this more than not on both compilation-style albums and concept-style albums. As stated above, album flow is interpretive... so go with your instincts.
I hope this long post helps. Good luck!
Joshua