Am I sharing my IP address/ location with my host instance?

Yes. If you connect to any server whatsoever, the server will have to know your IP, otherwise it can not send any data to you and the whole connection cannot be established. With your IP, one can figure out your (rough) location.

is there a log of my view history

As far as I can tell, yes. There is the option “show read posts” in your option menu which hides posts you have already read. In order for this to work, your read history has to be saved somewhere.

are there general privacy concerns that I am not thinking of?

There are always privacy concerns when accessing/using any service or server on the internet, at the end of the day it comes down to protecting yourself and using services you trust.

A potentially specific issue with federated, decentralized and self-hosted services such as lemmy is that the people who are running the servers are mostly hobbyists. Most will probably also work in IT professionally, but in general, people who host lemmy are doing it in their spare time at their own cost. This could potentially mean that they have less resources to secure their servers and the data on it than a multi-million dollar company.

Another thing to keep in mind on lemmy is that private/direct messages are not encrypted, which means that server admins can read your direct messages (there is a warning about this when you write a direct message).

I do not want to be in a position where a Government creates an instance, and allows them to monitor.

I’m not quite sure if I understand your worry here correctly. In general, most of the content that is posted on lemmy is publicly available anyway, so they wouldn’t even need an account to get that information, let alone their own instance.

And if governments have an issue with a user where they want information on a user, they can just contact the site admin and demand the information from them. So if you are planning on posting stuff that is considered illegal where you are from or if you are planning to access content that is considered illegal, Lemmy is probably a bad place to do that