Here is what I would do. Qualifier here - I am with Schwab and have used Fidelity years ago.
I would call.email each company you are considering and ask them to schedule a time to meet with a representative over the phone or video conference. Have all of your questions, or at least most, already prepared and write the answers down and as new ones come, write them down for each company. Ask about fees, investing systems/programs, what advice is available for free, what costs, and what products are available.
I took care of all our investing for many years through my earning years and right up to retirement. I consolidated those accounts into one place noting that you may have several different accounts such as taxable, 401 (k), 403 (b), Roth, and just a basic savings. They each have just enough differences to be a pain. Always let the company do the work for you as far as transfering money. I used a couple of Schwab's Self Directed investing strategies and they worked well. Eventually I reached a point where I just needed some advice from a pro for trusts, Charitable Giving, and eventually RMD's. Also, our portfolio had reached a point where my Schwab rep suggested I look into a Consultant. There are dozens out there who work independently of Schwab, Fidelity and the rest. They charge a fee, usually around 1% to manage everything for you.
For example, my advisor calculated all the what ifs of RMD and whether to convert them to Roth or just pay the tax. He also helped me set up a Charitable Trust that we use for all of our non-profit giving. We made it known through the interview that we Christians and do not want money spent on various companies that do not align with our values. They all pretty much have those types of things. What you are doing is essentially giving that rep access to your account to perform trades at no fees. A few years ago, we had some money in basic bond funds and they were getting hammered but have since come back. During that time I sent an email and asked if we could just devote a large portion of our fixed income to corporate bonds which means Walmart might put out a bond at 5% to borrow money for something instead of going to a bank. He took care of all that, I just could see the trade confirmations coming in.
At one time I loved reading prospectus of companies and funds and invested in funds and individual stock. Now that I am 71, I feel less inclined to do so and letting go of the wheel was not difficult at all with the person I trust. Hope this helps.