Look online first to find out as much as possible and get acquainted with terminology etc. what is Form E etc.
Petition to divorce can be done online or via solicitor (cheaper if you do it yourself) but you will both need a solicitor.
Look up a solicitorss. I chose a local one that I met face to face. I believe you can use an online one (again they may be cheaper?).
I decided not to try and save on a solicitor as this divorce is not amicable as far as my husband is concerned and he still wants to get his own way. (As usual).
I googled local solicitors and looked for individuals that were partners and specialised in family law and had been doing it for years. I also looked for someone who was part of Resolution.org. It means they look to mediate rather than going to court.
They often offer a free chat of 20 mins to 40mins. I called a couple and chatted and chose the one I have now.
I have had one face to face meeting (one and a half hours) where she explained everything and forms etc. my husband complained about me using a solicitor, but then had second thoughts and he has had one meeting with his too.
That is as far as we have got.
Best of luck. It’s one of those things where you start off knowing nothing, but quickly start seeing how it all works. It’s a bit of a steep learning curve but hopefully yours will be straight forward. Remember to ask hourly rates, and don’t be shy about asking how to keep costs down if there’s easy grunt work you can do yourself. It will be expensive.