Counting lengths is the next thing to learn after breathing. You'll get there. I always do something on the tenth length, sometimes it is take it easier, sometimes it is do it as a fast as possible, whatever, just mark it and go again.
Two hours though is a very long session, mentally as well as physically. You won't get any benefit that you wouldn't get in doing a 45 minute session if you do the 45 minute session right. Do two hours now and you will soon be sick of swimming. (well I know I get fed up with it) unless you have a real structure. Plus you risk injury doing a session that long when comparatively new to it.
Counting lengths is the next thing to learn after breathing. You'll get there. I always do something on the tenth length, sometimes it is take it easier, sometimes it is do it as a fast as possible, whatever, just mark it and go again.
Two hours though is a very long session, mentally as well as physically. You won't get any benefit that you wouldn't get in doing a 45 minute session if you do the 45 minute session right. Do two hours now and you will soon be sick of swimming. (well I know I get fed up with it) unless you have a real structure. Plus you risk injury doing a session that long when comparatively new to it.