hey man i feel your pain, Im 6 foot and for the longest time was only 150.
Youve probably heard it before but you need compound movements at high wieght to bulk up. This includes chin ups, push ups, bench press, rowing, squats, deadlifts etc.
But above all is LEGS, legs will make every muscle bigger as it triggers growth hormone production. Personally i was only able to keep perfect form for squats using the bar plus 10s on each side, which is pretty pathetic imo. So i started from the basics, 100 lunges per leg on leg days, 2 sets of split squats(aim for 25 each set), 2 sets of wide stance squats no
weight (again 25 a set). I can know do 4 sets of 12 reps squats with 25's on each side (95lbs) total with perfect form(which is really important). Idealy you should aska trainer at the gym to watch your gym, but if u cannot just make sure your back is flat and you go down until your thighs are parallel with the floor.
I peronsally do not bench because i have rounded shoulders which is due to sitting in front of the computer and having my chest stronger than my back. However it is up to you, but do not forget to workout your back as well.
As for diet I alot of meat and alot of veggies, while avoiding too much fat, salt, and otherwise unhealthy foods. I drink lots of water and have 2-3 protien shakes a day. I peronsonally avoid really fatty because I am trying to look cut for new years(big night) but if all you care about is
weight gain go for it. As well make sure you go to bed full every night.
Best of luck, oh btw I am now 155, having gained 5lbs in the last 3 weeks, which is amazing progress for me. If you would like more info feel free to send me a msg.