401K >> Rollover IRA

Hello everyone,
This is a follow up from a question I posted in the course and I would love to post it here so it may benefit everyone. I had a 401K from my previous employer in Fidelity, so I ended up doing a Rollover IRA, and I am currently in the middle of transferring a ROTH IRA from Acorns to Fidelity. This is where the fun begins, I was thinking that I could maybe merge those 2 accounts into just one (I don’t know which one, help?) and keep on contributing the max that I am allowed. One tiny issue though, I don’t have a job-job (no W-2), mainly I do side jobs to cover my day to day expenses and bills, however I do have a monthly income that is tax free. This is what is on my mind lately:
If I can’t merge those 2 accounts I was thinking of putting a Target Date Index Fund inside my Rollover IRA, but then I don’t know what to invest on my ROTH IRA once it’s finally transferred. Any tips are greatly appreciated. My apologies I know this is a lengthy post and I hope I made sense.