On this land you are able to build 1 single family home. Hillside homes have a min sqft requirement before you are able to build on them. First and longest process will be to get all the lands into 1 division. Currently they're subdivided into 4 parcels. After you you get that complete next would be planning to get permits ready for this, which would happen at the same time as getting all 4 parcels into one. Since the land total with all 4 combined would be 6,500sqft you would be able to build a maximum of 2800sqft at best hillside. Because hillside you are able to do .45 of the land total. Don't forget hillside has different setback requirements. Furthermore, have to look into sewer lines and all if anything is near.
To sum it up in my opinion below
1) getting plans and permits approved would take min 1 1/2 year.
2) It is hillside, your cost will increase. If you were to build a 2,300sqft home, you would be looking at 550,000 to 650,000k in cost to build it out. That does not include city permit fees and architect fees. City permit fees would run you about 30k-40k and architect fees probably 20k.
Personally if you want to invest in land stay away from hillside as your first project.