Data transfer from old phone and app store

Nomalt

So I recently made the switch to GrapheneOS on a Pixel 8a (yay!), ready to start an adventure to degoogle as much as I can. I have two questions (for now):

How do I obtain apps without using Google Play, If I really must use it I will certainly do so in another profile, but if i can go with something else I will. I heard F-Droid and Aurora store are not trustable and should not be used. Ialso heard about Obtainium but will I find what I want here? There is also Accrescent apparently on the Graphene App Store, is it good?
Secondly, I want to transfer some data from my old phone, mainly messages and contacts, I will transfer docs and photos manually. I have the Phone Clone app on my old phone that can do this, is it a good idea? Does the data transfer to somewhere else I wouldn't want to, is it any vulnerable, what are the options?

Thank you a lot for you answers.

chinook

Nomalt I suggest you start with https://grapheneos.org/faq
Then go for the forum (it has search function in the top right of the page): https://discuss.grapheneos.org/d/55-best-way-to-install-apps

what app store use depends on your risk appetite and requirements :)
Accrescent seems to be recommended. Aurora is generally less recommended than Google Play store, F-Droid is generally not recommended due to the inherent flaws.

Concerning messages and contacts, you're best supported by your dialer/sms messaging app. GOS backup/restore support leaves a lot to wish for. Don't have experience with Phone Clone app -- in my case I didn't manage to migrate anything from the old phone, so I had to install all the apps myself, and then transfer app backups

Nomalt

chinook I did not find answers to my questions on the faq nor the forum that's why I asked here. So there doesn't seem to be a satisfying alternative to the Play Store... There is next to nothing available on Accrescent, and Aurora and F-Droid are lesse secure than Play Store... Alternative would be to look for the apks directly from the githubs pages but not all apps have this and you will have to look for the updates yourself. Anyway I'll try to find another solution. If I don't I will have to use Play Store for everything...

chinook

Nomalt FAQ contains answer to your backup question, but more importantly this very forum reference contains I think all the answers you look for.

https://discuss.grapheneos.org/?q=install%20apps%20

We had a long discussion about app sources and Aurora in particular, a week or two ago. There's no point in discussing that again.
We also discussed backups and Seedvault in particular, many times.

If you have further questions, sure, ask away.

There is next to nothing available on Accrescent

yes

Aurora and F-Droid are lesse secure than Play Store

yes

Alternative would be to look for the apks directly from the githubs pages

obtainium? It supports auto-update.

Nomalt

chinook Okay thank you! I finally found a way to transfer SMS data (using SMS Import/Export) and started to use Obtainium for FOSS apps. For the rest of the apps that I want to use that are not open-source I think I will create another profile for setting up Play Services.