New songwriter (piano kid → lofi + melody/lyrics)

Hey everyone! I’m just starting to write my own songs—mostly instrumental/lofi “pure music,” and a few ideas with topline + lyrics. I’m stuck on a couple things and would love guidance from folks who’ve done this.

1. US copyright: what should I actually do after I finish a song?

I’ve heard that copyright exists automatically once a work is “fixed,” but that registration is important if there’s ever a dispute.

If I have a finished track (MP3/WAV) and a lead sheet/lyrics, what do I register and how? Do I file “musical work” (composition/lyrics) vs “sound recording” (my recording) separately?

Any tips on using the US Copyright Office eCO system (what to upload, common mistakes, best practice for titles, collections, etc.)?

If I have several unpublished songs, is there a legit way to register them as a group to save time/cost

2. Apps / DAWs: best tools for lofi + writing?

I can play piano but I’m new to production. What do you recommend for:

DAWs (Mac/Win): Logic Pro, Ableton Live, FL Studio, Reaper, GarageBand, BandLab, Soundtrap—pros/cons for lofi workflow?

Mobile/sampler apps: Koala Sampler, Auxy, etc.—worth it?

Go-to lofi tools: tape/lo-fi effects (RC-20, iZotope Vinyl), simple drum packs, free instruments (Spitfire LABS), and any must-have plugins?

3. Where to publish as a beginner?

Is it smart to start with SoundCloud / Bandcamp / YouTube first, or go straight to Spotify/Apple via a distributor (DistroKid, TuneCore, CD Baby, etc.)?

If I plan to release originals, should I sign up with a PRO (ASCAP/BMI/SESAC) now? Anything I should know about The MLC or Songtrust for publishing admin?

4. How do you check if your melody is original?

Sometimes I worry I’ve accidentally absorbed something I heard years ago. What’s your method to sanity-check?

Any tools/workflows you use to search for similar melodies?

Practical tips (e.g., change contour/rhythm, reharmonize, key/mode shift) to avoid subconscious copying?

Any advice would be amazing. Thanks!!