[Which Warframe To Craft First?]

I'm new to the game. Just about 1 week ago i started play this game. Someone in-game suggested me to create new warframe for beginning. He told me that Rhino will do good at earlier game. But I think Excalibur might to much better, no? Well I'm just having fun with Excalibur's wave attack xD And he told me Rhino is good at tank. I usually play solo.. so what do you guys think?? Or are there any warframe which is much more better Rhino or Excalibur that can easily crafted at beginning for solo.

[Login Failed. Check Your Information?]

I am sure I have keyed in the correct email and password but still the error message pops out. Can hardly login into the game. Even I manage to do so, no longer then I will be disconnected and unable to login again... The same error message keep pops out and I cant find any solving method for this issue. Anyone know how to fix this problem??