Loomis Ca. To Lk. Tahoe

Going east on US 50 across Nevada fill up in Fallon as it is the last sizeable town until Ely. If you travel at night the range is not fenced so it is possible to have a black cow standing on the black road during a black night. Be careful. Rural eastern Nevadans are friendly, the least visited national park is Great Basin with Lehman caves east of Ely near Baker, and traffic will certainly not be an issue.

You can't get over the mountain without a climb. I-80 will have the least grade so I suggest I-80 to Truckee and 89 to Tahoe City and around the north shore to US50.

Many big grades east of Lake Tahoe on Hwy 50

Since you will be in Loomis, the most direct route will be I-80 to Hwy 89 near Truckee. But you will have to climb over Donner summit (about 7200 ft) to do it. No way to avoid the climb over the summit. You could work your way over to hwy 50 by way of Sierra College Blvd/Hazel Ave and then head up 50 over Echo summit, but you will still have a pretty good climb to reach Tahoe. My preferred route would be up 50 over Echo summit which will take you right by the lake and then on to Carson City and beyond on hwy 50. You will have no issues traveling hwy 50.