I need a training plan :)

If you can only train during the weekend I would reccomend some really heavy lifting where you go balls to the wall both days and maybe split into upper-lower or push-pull on the two days. For most people I would reccomend not going that hard every workout, but since you will have the entire week to recover I think it will be fine.

What is the reason you don't have time during the week? And what kind of lifestyle do you have otherwise? If you have time for some trigger sessions during the week that could help a lot. You don't need more than 15 minutes, but just doing some bodyweight exercises such as pushups, wall sits, bench dips and similar things could really help you out.

First off, two days a week training, with the hope of gaining muscle just won't cut it... in my opinion... 4 days a week (at minimum) would be better suited for what you are trying to do. Look at successful bodybuilders/weightliftrers. They didn't get that way by working out only two times per week.

Secondly... if it is really important to you, you WILL find time. If not, you will find excuses (sorry). I am 59 years old. I alternate between lifting and cardio (spinning), for 5 days a week. I had been working out in the evenings after I get home from work, but with the weather getting nicer, the wife is increasingly liking to go out after work... so... I now get up at 3:30 am to get my workouts in. I make/find the time to do what's important to me.

I don't know you, but I do know that you can do it! Dig down deep... pull up your pants, and go for it!