I designed our house. I had three years of drafting in High School because at the time I wanted to be an architect. I tried a few of the simple home design software packages and they were a PITA and would not let me do what I wanted.
I had bought an excellent package back in the late 80s or early 90s that was cheap but full featured. But Autocadd bought the company and shut it down.
I found another company called General Cadd that carried over the command line interface of the old program. The program is not cheap and it requires some effort to learn. It likely would help to have a drafting background. They do have a free trial version. I still use the program for other projects.
I was so frustrated with the design packages I tried I ended up starting our house design with my old drawing board and my old drafting equipment. Then I found General Cadd. It was easier and faster for me to do the design with paper and pencil than use the other packages I tried.
Skip the Architects. They charge a fortune and for a simple house they are overkill. Find an design/build engineer or a draftsman. If you are going to design the house you do have to know about allowable spans and loads. To span a large distance can require certain materials that can effect other areas of the design. You have to be aware of these things.
Speaking of spans and loads. The group(SPIB) that sets the design values of SYP is proposing to DECREASE these values up to 35%. Their testing has shown a decrease in strength of pine. There is more testing happening so who really knows what will happen.
The point to the last paragraph is you need to understand certain issues or hire somebody that does. You can find books or web sites that can help you learn these things. The Journal of Light Construction(JLC) is excellent and has a website holding their previous editions that goes back decades as well as a very active online forum.
For design details of the walls, roof, foundation, etc I HIGHLY recommend the book for your climate written by Joseph Lstiburek,
Builder's Guides. I used his design details on our house. He is a PE PHd. I was reading the JLC forums and Lstiburek was having a "debate" with a guy selling building materials. Lstiburek impressed me with his knowledge and common sense. Then I found his books and found out why he impressed me.

His books might be available on Amazon and other places cheaper. I just put in the Building Science link.
The Building Science site also has great information if you are going to be designing your house. Even if you have someone else do the design they have some very good ideas to do and things to avoid.
Later,
Dan