If you are into supplements, don't waste your money; spend it on food. All u really need is some protein to help you meet your macros and some pre workout for a boost before you lift.
As far as a plan I'll tell you this, and it works. I just eat a lot of healthy food and I monitor my bf. you want to eat lean meat, eggs snd dairy, veggies, a lot of whole grain bread, pasta, oatmeal. I aim to eat 5-6k call a day and if I starting putting on fat/weight too fast I dial it back. If you prefer to use mathematical calculations in setting your macros thats more precise, but this works for me.
Those articles on my blog I wrote a long time ago and I have a different philosophy now, fast food is not the way if you can avoid it but it does work.
Training has to be intense. Plenty of carbs will help you to get stronger and keep the intensity up. You should find a partner to lift w bc you need a spotter if you want to get stronger which will help you get bigger. Usually lift one muscle group per day, but I switch to mix a few together.
if you have a weak area you should work that group twice a week, and it really helped increase my bench to do it twice a week.
You should be mixing core stuff in all the time everyday though and you can switch the order of these up however you like. One thing that I believe really helped me recently was to focus a lot on one lift each day to get stronger on and add mass. For instance, chest day I will bench around 5-6 sets. First set around 8 reps to get a feel, then 4 reps, then Max out one rep for 2 sets (this is where you get stong) then I do one or 2 sets of 10-12 reps. The other lifts that day I do more reps and focus on contracting.
This helps a lot w strength endurance and mass and makes sure u are really pushing yourself hard each day. If you've been stuck at that weight you need to say fck it and go all out w your eating and training and make it your priority. You will see the lbs come.