its all up to you on what line to go, if you go junyo then you'll probably try out mogami cv till 60, if you go hosho then get it to start your real cv experience

If you have enough money then buy a Hosho. Credit gain in a CV1 is far better than Mogami/Oyodo and buying other CVs will get a LOT easier.

IJN T1 fighters are worse than terrible i'd suggest using Shindens.
Why? IJN T1 is slow as heck. You can catch bombers mid field and they still won't kill them before they drop bombs on some BB... hell those bombers might even kill your T1 because of your pilots low ability.

Mog CV does have the advantage of not being a CV so you can play without the pressures of being a flag etc.

Since I recently had a similar question I can verify from personal experience what they are saying. Rather than jumping straight on the Hosho I lvled to the Mogami remod. But then I found that it would be difficult to afford the Ryujo. If you are wanting/needing credits then I suggest, as Sonlirain pointed out, to get on the Hosho. However, as Mako089 points out, the Mogami isn't classed as a cv (I remember the days when it was, same as the Oyodo) so there is no pressure to perform. The Hosho itself isn't a whole lot better than the Mogami Remod and if it wasn't for the credits would be almost wasting a cv spot.

Mogami 44. You can join any room you want, mount any planes you want, and have a wide variety of r and t slot loadouts.

Agreed on the Shindens. The Claudes can't catch anything.

I should also mention that the Hosho is unarmed and lacks spots for people who are not pilots or the BO, unless you only use a couple of pilots.